Hardwick, a Pro Bowl selection following the 2006 season, spent training camp on the physically unable to perform list. He would have had to miss the first six games of the season if he wasn't removed from the PUP list by Saturday.
The Chargers also released linebacker Carlos Polk and placed tight end Scott Chandler on injured reserve Saturday.
Polk spent the past seven seasons with the Chargers with his primary role being on special teams. Only defensive tackle Jamal Williams and long snapper David Binn have been in the organization longer than the 31-year-old Polk.
Turner said it was hard to release Polk, one of 20 players who were cut.
"When you have a veteran player like Carlos Polk who has been here and been a big part for us, those are tough," Turner said. "We knew we were going to have some tough cuts at the end. We have young talented players that are the future of this team and can contribute right now and can do things for us in the kicking game and do things for us in special situations on offense and defense."
Chandler injured a toe in the final minute of the Chargers' exhibition finale against San Francisco on Friday night. Turner said the second-year player will see a specialist in the middle of next week.
One undrafted free agent overcame long odds to make the roster -- fullback Mike Tolbert of Coastal Carolina.
"It was difficult," Tolbert said. "This is one of the three elite teams in the NFL so I knew it was going to be hard at first but once I got out here and realized I could play with these guys, I had it set in my mind that I could actually play this game and play for this team."
Also, starting inside linebacker Stephen Cooper began serving a four-game suspension Saturday for violating the NFL's steroids and related substances policy. Cooper is eligible to return to the Chargers on Sept. 29, the day following the fourth game of the regular season.
Copyright 2008 by The Associated Press