Get ready for quite the chess match Sunday.

When the Chargers and Vikings square off in Week 3, the head coach of each respective team will be reaching deep into his bag of tricks to try and slow down the other.

The twist? Brandon Staley and Kevin O'Connell also happen to be best friends.

Chargers.com spent time with the pair together at the Arizona Biltmore resort in late March when the two were in Phoenix for the 2023 NFL Annual League Meeting.

Even six months ago, the two knew the challenges that await each other in three days at U.S. Bank Stadium.

"First and foremost, the hardest coaches to coach against are the one that understand the intent of plays that they're being attacked with," O'Connell said. "Brandon knows, in the pass and run game, the 'why' behind what we're doing offensively. He knows what we're trying to accomplish and knows how to use his scheme.

"The playbooks are one thing, but it's his activation of his guys. And then he's one of the best defensive playcallers in the NFL," O'Connell added. "But with the system and the background he comes from, there's a secret to the play-calling element and keeping offenses off balance with the different tools that he has such an unreal ownership of."

O'Connell kept going, diving into specific detail as to what he expects the play-calling gamesmanship to be like Sunday.

"It makes it really hard because you can never quite get comfortable," O'Connell said of Staley. "And if you can't get comfortable as a coach, it's hard to get your players to that kind of winning edge of being able to just go play.

"You're trying to balance what he's calling to take away what you're trying to call for the best parts of your offense," O'Connell added. "The great defenses and great defensive coaches in this league take away what you do well and make you play with your changeup and your slider and your curveball. You better be really good at those things because they're going to be really good at different layers."

Staley knows he's in for no walk in the park, either. He understands firsthand the difficulties of what O'Connell will present on offense.

"You have to defend all 11. He makes you defend everybody on the field. I think those are the toughest offenses to defend," Staley said. "He knows how to utilize all 11 guys on the field and puts the pressure on you defensively with pace, formations, motions.

"And he can get the quarterback playing at a high level because he understands defenses so well," Staley added. "I think you just know every snap that your guys need to be prepared because any snap could be a tough down for you."

Staley and O'Connell have gone against each other numerous times before. The pair were colleagues and coordinators on opposite sides of the ball with the Rams in 2020.

But both their friendship and football journeys will come full circle in Week 3 when Staley's Bolts travel to Minnesota to take on O'Connell's Vikings.

Here is an inside look at how their friendship impacted both their coaching careers and personal lives, and what the two expect the emotions to be like Sunday at U.S. Bank Stadium.

Sitting at a patio table outside the Biltmore resort, O'Connell tried to get an early victory when asked about the first time he met Staley.

"I had heard about him and had known about him," O'Connell said of Staley. "But we became very close, very quickly.

"I was hired the day before, just for the record," O'Connell added with a smile.

Staley recalled his first impression of O'Connell.

"When I was interviewing, they were finalizing the deal with him," Staley said. "[Rams Head Coach] Sean [McVay] was effusive in his praise for his newest offensive coordinator said that we would be great teammates and companions. Who would have thought?

Staley later added: "A lot happened in a short amount of time … there was a lifetime full of memories in one year."

Staley and O'Connell were colleagues for just one season in 2020 before Staley was hired as the Chargers Head Coach.

Football-wise, the former college quarterbacks were immediately drawn to each.

Staley has a penchant for coaches who happened to play quarterback in college. It's why he has seven of them on his staff.

At training camp this year, Staley commented on counting nearly one-third of his staff as former college signal callers.

"I don't think it's a coincidence," said Staley, who played at Dayton and Mercyhurst College. "It was the same way when I was with the Rams, there were a bunch of quarterbacks [on staff]. I think that position is just naturally attracted to coaching.

"Some of the best coaches I know are former quarterbacks, and I just think it's about the way you think, the level of football you've been exposed to," Staley continued. "When you play that position, you're responsible for all 22 [players] on the field.

"It's one of the few positions like that in all of sports, and it naturally leads guys to want to coach," Staley added. "I love having that around our team because it multiplies the impact of that position."

When Staley says that some of the best coaches he knows are former quarterbacks, it's an obvious nod to O'Connell, who starred at San Diego State before becoming a third-round pick of the Patriots in 2008.

As the two got their feet wet together in their early days with the Rams, Staley and O'Connell leaned on their past as they dove into the Xs and Os.

"The coolest thing about Brandon that not everybody knows is that this guy has a love of offensive football and quarterback play," O'Connell said. "He knows it, not only what he was around as a player but he's also really, really studied the game and studied quarterbacks to the point where I learned things from him.

"His perspective was great for me because, shoot, he's got more things archived — plays and video archives — than most offensive coaches do," O'Connell continued. "That speaks to why he's so good at what he does defensively because he truly has the answers to a lot of the things that other coaches may be searching for.

"He's really embraced that and has a world-class knowledge," O'Connell added. "I found it fascinating when we actually started discussing it, that the football discussions weren't combative as much as we agreed on a lot of things. But the things I learned from him, I'm still using as a coach to this day."

Staley didn't play quarterback in the NFL. He was 16-5 as Dayton's starting quarterback in 2003 and 2004 before transferring to Mercyhurst.

But his time under center has helped mold him as a coach, and that knowledge further deepened while working with O'Connell.

"Kevin's experience as a player, I felt like he was trained the right way," Staley said. "Then I think transitioning to coaching, it's a difficult thing for people to understand that what you know as a player and then applying it to coaching. I was able to see players that he coached at different stops and how they improved.

"Then up close, something that makes a good coach is your foundation and knowledge. Kevin has such a unique background in both ways, and a unique ability to adapt and the translate it," Staley continued. "Certainly, we were with Sean, who is an outstanding offensive coach. I was so impressed with what Sean learned from Kevin and then seeing them team up and having Kevin coached Jared [Goff] the year I was with him. "And then after I left, to see him team up with Matthew Stafford and win a Super Bowl. And then what he's doing now with Kirk [Cousins].

"What I learned from Kevin is that it's not just what he knows but it's what he can teach the players and get them to believe in it in the most crucial position in sports," Staley added. "And how he's done that with different types of players in different stages in their careers. I've really tried to take that to Los Angeles with Justin [Herbert] because Kevin is as good as I've seen coaching quarterbacks."

With both playing catch up a bit and trying to get their schemes implemented back in 2020, Staley and O'Connell — along with McVay — chose not to attend the NFL Scouting Combine in Indianapolis.

Those few days in Thousand Oaks help set the foundation for the rest of the year.

"I remember what kind of got us off to a good start from a friendship standpoint was that we stayed behind from the Combine," Staley said. "Sean, myself and Kevin stayed back while everyone else went to Indy because we were trying to get our systems up and running.

"That week spent behind … we were the only two in the office with Sean and we spent every second together because our families weren't there yet," Staley added.

The Staley and O'Connell families would soon make the move out to California. And with a global pandemic unknowingly on the horizon, the groups would become closer than ever.

Back in March, Staley and O'Connell each lit up when talking about their respective families.

Staley is a father of three boys — Colin, Will and Grant — and is married to Amy, whom he met while coaching at Northern Illinois.

O'Connell and his wife, Leah, have four children — Kaden, Quinn, Kolten and Callie. Both families have children around the same age.

In those early days with the Rams, Staley and O'Connell were just two coaches who leaned on each other while away from their loved ones. And once their connection grew, they knew something special was brewing.

"You move without your family at first and we're both living in a hotel. Had a few dinners just enjoying each other's company," O'Connell said.

"You learn, 'Hey, he's got three kids and I've got three kids [at the time]. Both of our wives are former athletes so it was like, 'We've got to get these two ladies together. Forget us.' Then our families growing close is really where it became something special," O'Connell added.

But unbeknownst to everyone, the COVID-19 pandemic would soon arrive and seemingly throw the world off its axis.

"COVID led us to probably a relationship that will last forever," Staley said. "It was every single day that the O'Connell and the Staley families were together."

A former first-grade teacher, Amy Staley stepped up and began homeschooling children from both families, who lived about 15 minutes apart.

"She converted her back casita to a classroom, and we took turns," Leah O'Connell said. "Every other week we'd be at her house, then at my house, and did our P.E. days at the beach.

"It was really legitimate," Leah O'Connell added. "We bought curriculum, and I took the littles, and she worked with the bigs on the main subjects."

Due to their demanding schedules, Staley and O'Connell popped into the classrooms when they could.

But they made sure to be the only two in attendance for the kids' Christmas program, which featured a full nativity scene.

"We'd go from the office to homeschool, there wasn't a moment where we weren't together," Staley said. "We did everything together for an entire year.

"We had a special year together personally and professionally and we accomplished a lot as a group," Staley added. "I think we leaned on each other a lot throughout that whole year because it was a tough year professionally, too."

O'Connell added: "We had a decision to make with our families with what was the best route we could take moving forward. With Amy's background in education and my wife's background in wanting to get our two families together … it was a special time. It doesn't seem like it was just one year."

Staley was on the rise when he was hired by the Rams in only his fourth NFL season.

He had spent two years as Chicago's outside linebackers coach in 2017 and 2018 before joining the Broncos in the same role.

But one of the league's top defensive minds landed his first NFL coordinator role in 2020 when he joined McVay's staff.

That meant daily battles against a head coach who is among the most innovative and creative at his craft — plus a rising coordinator in O'Connell who had plenty of bright ideas and concepts of his own.

The end result?

"It was super competitive because you were in this unique environment with Sean," Staley said. "The coaching staff we had, there were a bunch of superstar coaches that are all doing amazing things. There was a healthy spirit and we all knew the Rams were benefitting.

"And we all knew, personally, we were benefitting because of the competition. So, it was going both ways," Staley continued. "We knew our team's goals and our personal goals were coming alive because we were bringing out the best in each other.

"It was just a healthy, competitive spirit that was every day. You felt it every day," Staley added. "What was special in our time together was that when we took the field, we felt like we were the team to beat because of what we did on a day-to-day basis."

O'Connell added: "We all knew it was something special kind of brewing because of the quality of person and player and human being that built that culture. It never crossed the line. It was always professional and energetic, always positive. I tried to take that to Minnesota when I got there because of what I experienced when I was with him and Sean."

In charge of defense that featured the likes of Jalen Ramsey, Aaron Donald and others, Staley helped guide that group to be the league's top unit.

The Rams defense led the league in numerous statistical categories in 2020, including both points (18.5) and yards (281.9) allowed per game and first downs allowed per game (17.5) while also leading the NFL in EPA per play (minus 0.141).

O'Connell said he marveled at the performance of Staley's defense each week but added that he wasn't surprised by it given how he had an inside look at the defensive coordinator's teaching methods.

And, O'Connell noted, the impact Staley made in 2020 would play an integral part in the Rams winning the Super Bowl the following season.

"Really watching him teach in unique circumstances, a lot of times on a Zoom screen, and then watching it come to life with the players' ownership of it," O'Connell said. "Defensively, they're hitting the field against an offensive unit that had been running the same offense for five years at that point. And they didn't miss a beat.

"That really energized Sean and allowed training camp to be very competitive. It ultimately made us a better team," O'Connell added. "And I tell people this all the time … we were still feeling the benefits of that in 2021 when Brandon had become the head coach of the Chargers. The Rams were still reaping the rewards from bringing him in the year prior of his belief and understanding and ownership of his system."

When the Chargers and Vikings kick off Sunday at 10 a.m. (PT) in Minneapolis, Staley and O'Connell will be all business.

But the two will undoubtedly share a moment pregame, perhaps with their families, and reflect on so much.

How much they leaned on each other during a chaotic year. How much they each helped each other get a job as an NFL head coach. And how they built a friendship that will endure for the rest of their lives.

O'Connell had a special moment of his own during the 2022 season when he went up against his former head coach in Bill Belichick.

He expects Sunday to be an even bigger deal.

"That was a unique feeling [against Belichick] but I'll probably multiply that by about 10 when he's on the other side of the field," O'Connell said of Staley. "Just because he truly is one of my best friends.

"It's not anything we try to hide and it's not anything we'll try to hide leading up to that game," O'Connell added. "But I'm sure it will be competitive as all get up. I have so much love and respect for each other and our families that it's going to be pretty unique."

Staley felt a similar feeling in 2022 when he got a win over McVay in Week 17. But he, too, acknowledged the feeling will be enhanced this time around, especially on the road.

"It was hard going against Sean for the first time. Kevin and I are the best of friends so it's going to be a different feeling," Staley said. "But it's going to be in Minnesota so it's going to be super hostile. I don't know if he'll be able to hear me through the SKOL Chant. But also, in a way, it's a dream come true.

"You try to surround yourself with people who are special and to have one of your best friends who is also an NFL head coach, and to have our families be so close, it's going to be a memory," Staley continued. "Off the field, it's a memory.

"On the field, it's going to be tough and rugged and bring out the best of both of us," Staley added. "And it's going to be one of those things that you're never going to forget."

Vikings Writer/Editor Lindsey Young also contributed to this feature.

Bolt Up!

Secure your Chargers Mini Plan today! Click here to learn more.