The Chargers returned to Chargers Park on Thursday after a late-night practice at Qualcomm Stadium on Wednesday. Veterans TE Antonio Gates, C Nick Hardwick and ILB Takeo Spikes took the night off to allow coach Norv Turner some extra reps to evaluate other players. The practice turned out to be one of the most energetic and hard-hitting of camp.  

“I thought we had an outstanding practice last night,” coach Norv Turner said. “Today our guys came right back, and we had great situational work.”

What stood out: OLB Demorrio Williams (free agent, Chiefs) blew up two separate blocks set by RBs Jackie Battle and Ryan Mathews. But Mathews was solid overall. He broke several long runs and found the end zone three of four times in a goal-line drill. WR Robert Meachem, who exited Wednesday night's practice with a tweaked knee, showed no signs of an injury and had several receptions, including at least two for TDs. TE Ladarius Green (round four, 110th overall) had his best practice by performing well as a blocker and receiver. QB Kevin O’Connell, who was signed Monday, fumbled two snaps in limited reps and in general looked uncomfortable.

Position battles: Several players who probably will not be starters saw action with the first-team. This included a few who may not even make the 53-man roster: C Colin Baxter at guard, ILB Bront Bird, C-G, CB Greg Gatson (undrafted, Arkansas), TE Ladarius Green, Rex Hadnot (free agent, Cardinals) at center, OT Mike Harris (undrafted, UCLA) at LT, RB Michael Hayes (undrafted, Houston), TE Dante Rosario (free agent, Broncos) and CB Shareece Wright. Gatson, Green, Hayes and Rosario appeared to make the most of the opportunity.  

“What I tell our guys and I tell them this about three times a week, is don’t get caught up in [where you are playing on the depth chart],” coach Norv Turner said. “We are working towards playing our opening game and there are a lot of things we are doing in there. If you get caught up in that and start worrying about that it will affect how you perform.”

Injury updates: Starting LT Jared Gaither is the biggest concern. Gaither has only participated in one practice since he left the team’s first full practice with cramps last Thursday. He is expected to return in a few days, according to the San Diego Union-Tribune, but observation would suggest otherwise. Gaither’s body language was extremely poor as he sat on the bench for most of Wednesday night’s practice. When Gaither stood for brief periods he appeared to be extremely uncomfortable, and it would not be surprising if he is out for a significant time. G-T Brandyn Dombrowski (foot, cyst) has yet to participate, but is out of a boot. QB Charlie Whitehurst, WR Eddie Royal, WR Richard Goodman, CB Marcus Gilchrist, OLB Larry English, G Johnnie Troutman, T Phil Trautwein and DE Corey Liuget worked on the rehab field and are expected to return in a few days. SS Atari Bigby returned to practice but saw limited participation.

What's next: The Chargers will have a walk-through on Friday morning. This will be followed by a full practice from 3:45-6:00 p.m., which is open to the public.  

Follow Chargers reporter Dan McLellan on Twitter @CBSSportsNFLSD and @SanDiegoSports.