Here are five takeaways from the Chargers' first training camp practice of the year at Jack Hammett Sports Complex:

No surprises – The 2019 Los Angeles Chargers don't need to make a ton of introductions. The roster and coaching staff are largely intact from last season's 12-4 campaign, making Day 1 of training camp crisp and efficient.

"It felt good to see everybody," All Pro safety Adrian Phillips said. "You could tell people went home and they were working."

"I think that's the best part, man," added safety Rayshawn Jenkins. "[It's] kind of like college. You come in, you're going to see some of the same faces – a lot of the same faces – and that's what I feel like we're doing here."

Mostly the same players, but a different team. Head coach Anthony Lynn made it a point to mention that last season's results don't carry over. He said his biggest concern is the team's mindset and making sure his players control what they can control – namely effort and approach.

Lynn said Thursday's practice was good, and he expects things to ramp up on Friday.

"I didn't want to go zero to 100 on the first day back, so we kind of eased our way into it," Lynn said. "Tomorrow, we'll be full-go. I'm just trying to keep everybody healthy and give them a chance to make this football team."

TE Hunter Henry's notable presence – Quarterback Philip Rivers connected with Henry for a big gain down the right sidelines during Thursday's practice, a familiar scene for a duo who hooked up for over 1,000 yards and 12 TDs from 2016-17.

An ACL injury kept Henry out for the entire 2018 regular season, but the 24-year-old tight end has been fully healthy since appearing in last January's AFC Divisional Playoff Game against the Patriots.

"It's great to have Hunter back," Rivers said. "It's a little bit of a weird deal because I think for everyone on the outside, it's like 'Wow, they're getting Hunter back.' For us, although he didn't necessarily play a ton in that New England game, we felt like we've had him back for some time now."

On Wednesday's episode of Chargers Weekly, general manager Tom Telesco said that Henry's full return is "huge for us," noting his ability to impact both the run and pass game.

"He looks good," Lynn said. "He looked good in the offseason. He looked good last year or we wouldn't have let him come back in that last game. It's good to see him back and having fun out there with his teammates."

JackBoyz bring the energy on the field (and on the podcast) – The Chargers' secondary is known for being the tone-setting position group on the football team. On Thursday, a pair of safeties brought that same enthusiasm to a training camp edition of Chargers Weekly, the official podcast of the team.

Adrian Phillips and Rayshawn Jenkins hit on several topics related to the upcoming season, including the high standard the DBs set for themselves – and each other.

"Hey, we're the last line of defense," Phillips said. "So nine times out of 10, if we mess up it's a touchdown or a big play. So, we feel like our energy has to be even higher than everybody else's and we have to have that confidence level – and we build it out on the practice field, so in a game it comes easy."

"Imagine you come into work, and you come around a bunch of energy vampires," Jenkins added. "… I'm not with that. So, we just try to keep that energy in the room, keep that high energy in the building."

NFL Network's Omar Ruiz also joined the podcast to share his observations from Thursday's practice. Download and subscribe wherever you listen to podcasts.

LB Thomas Davis turns back time – Entering NFL season No. 15, new Chargers linebacker Thomas Davis took the field Thursday for his first training camp on the west coast.

Since arriving to Southern California, the only remaining defensive player from the 2005 NFL Draft hasn't been acting his age.

"TD looks like he's about 24," Phillips said.

Before last year, Davis had made the Pro Bowl three consecutive seasons. Phillips likened the veteran to a rookie who's trying to prove something each day he steps on the field.

The former Panther has 158 career NFL starts. He's already made an impression on his new head coach, who wants to make sure Davis ramps up to the regular season.

"Thomas is a heck of a linebacker," Lynn said. "He's going to bring leadership to the linebacker room and experience, but first he has to learn our system. He's working his tail off right now every day to learn our system. I love his energy. Going through this camp, I'm going to hold him out some and make sure that he's fresh come Week 1. He's 36 years old, but he runs around like a 13-year-old."

On-field observations – Veteran defensive tackle Damion Square was working individually with first-round DT Jerry Tillery at the beginning of his first full practice as a pro. … Quarterback Easton Stick connected with wide receiver Jason Moore on back-to-back plays – a nice sequence for a pair of rookies. … Cornerback Trevor Williams made a sidelines interception. … In addition to finding Henry for a long gain, Rivers threw a dime to wide receiver Travis Benjamin, shades of Kansas City in Week 15.