The Chargers continued Organized Team Activities (OTAs) on Wednesday by holding the fourth of 10 scheduled spring practices.

The Bolts practiced for nearly two hours at Hoag Performance Center in helmets and shorts on a picturesque afternoon.

OTAs make up Phase Three of the voluntary offseason program. Phase Three consists of a maximum of 10 OTA practices where teams can run 7-on-7 and 11-on-11 drills. Live contact is not allowed.

Here are three observations from Wednesday's OTA practice:

1. Alt gets 1st-team reps

Spring practices are a time for tinkering and experimenting with different things, whether it's schemes or combinations of players working together.

That should be top of mind considering the Bolts still have 102 days until their 2024 season opener.

But the most notable part of Wednesday's session was that the Chargers shuffled up their first-team offensive line combinations Wednesday, with one group featuring Trey Pipkins III at right guard next to rookie Joe Alt at right tackle.

The Chargers opened Wednesday's practice with the same quintet we saw last week as Rashawn Slater was at left tackle next to left guard Zion Johnson. Bradley Bozeman was at center with Jamaree Salyer at right guard and Pipkins at tackle.

But the mixing and matching soon began when the Bolts went to 11-on-11 drills, with Brenden Jaimes coming in for Johnson. Alt then stepped in for Pipkins, who slid inside to right guard to complete the group.

Again, it's not even June yet so these combinations are nowhere set in stone. But it's clear the Chargers are trying to figure out their best five during OTAs.

Another offensive line group consisted, from left to right, of Foster Sarell, Brent Laing, Jaimes, Karsen Barnhart and Alt. But a few plays later, Salyer hopped in for Alt and played right tackle.

The Chargers are slated to hold another open OTA practice Tuesday before mandatory minicamp goes from June 11-13.

2. Harbaugh unveils new drill

The Bolts unveiled a new offensive drill Wednesday to help out quarterbacks and pass catchers.

Early on in the session, a contraption was wheeled onto the field that feature two large silver curtains attached to it.

The focus soon turned to an anticipation drill as pass catchers ran crossing routes behind the curtains, with quarterbacks aiming to hit them in stride once they passed the second one. This drill also benefitted the receivers, too, who could work on their hand-eye coordination as they ball arrived after they passed a blind spot.

Chargers Head Coach Jim Harbaugh got involved in the ensuing drill, which also featured the curtains.

Pass catchers were split into two groups as Harbaugh stood in the middle of the rack. He pointed left or right as a receiver made himself available just past an opening on a side of the curtain.

The Chargers four quarterbacks didn't know which side the receiver would pop open on, meaning the drill focused on their processing and quick decision making.

3. A focus on special teams

The Bolts spent a good portion of Wednesday's session working on special teams circuits.

The first chunk of practice focused on punt protection and coverage. Chargers Special Teams Coordinator Ryan Ficken worked with the interior blockers and rushers as JK Scott boomed kick after kick down the field. Derius Davis and Jaelen Gill were the returners.

The drill didn't feature gunners, as they worked on an adjacent field with assistant special teams coach Chris Gould.

Later in practice, the Chargers worked on the new kickoff format by focusing on both coverage and returns.

The NFL altered the kickoff rule this offseason with the biggest change being where players on both sides of the ball line up. A new-look setup zone features a cluster on players on both sides, with a returner (or two) back deep in the landing zone, which is from the 20-yard line and in.

Players in the setup zone can't move until the ball is either caught or hits the ground in the landing zone.

Ficken and Gould routinely instructed players after the reps, as everyone — players and coaches included — are getting used to the new format.

But, as mentioned above, the Chargers have four-plus months (and three preseason games) to tinker with it.