SAN DIEGO -- During a conversation with reporters on Monday, San Diego Chargers head coach Mike McCoy announced the defensive tackle Ricky Tjong-A-Tjoe suffered a torn anterior cruciate ligament tear in his knee against the San Francisco 49ers on Sunday, and is done for the season.
The undrafted rookie free agent out of Boise State suffered the injury with 13:06 left in the contest while trying to tackle 49ers running back Glenn Winston.
McCoy said the defensive tackle Kwame Geathers, who also suffered a knee injury in the first half of the San Francisco game, is having further tests done by the team's medical staff, so he did not know the extent of his injury.
Geathers was injured at the 7:23 mark of the opening quarter on a 4-yard run by San Francisco running back Carlos Hyde.
The Chargers are already thin along the defensive line, and those two injuries further weaken the Chargers' depth up front defensively. Starting defensive tackle Sean Lissemore (ankle) and backup defensive end Lawrence Guy (shoulder) missed the San Francisco game.
At 6-6 and 290 pounds, Kruger was a seventh-round pick by the Eagles in the 2013 draft. Kruger injured his shoulder during the 2013 preseason, and spent his entire rookie season on the injured reserve list. Kruger will likely work as a defensive end in San Diego's 3-4 defensive front.
After waiving 11 players on Monday, the Chargers have 80 players on the roster, and must cut down to 75 by 4 p.m. ET on Tuesday.
"It's the tough part of the business," McCoy said. "It's not a fair business, but it's all part of our jobs."
McCoy was asked about center Nick Hardwick, who left the game in the first half with a neck injury. Hardwick dealt with neck stingers the second half of last season, but McCoy said his veteran center is fine.
McCoy would not provide a timetable for the return of other players who missed Sunday's game, including Vincent Brown (calf), Manti Te'o (foot), Jahleel Addae (hamstring) and Marcus Cromartie (groin). However, Te'o was seen walking in the locker room on Monday without a protective boot on his foot.
McCoy also remained vague on the status of offensive lineman Jeromey Clary, who is on the physically unable to perform (PUP) list. Clary has not practiced since the beginning of training camp as he rehabs from offseason shoulder and hip surgery. But the Chargers have to make a decision by Week 1 of the regular season on whether to place Clary on the active roster or put him on the reserve PUP list.
"We've discussed it from the very first day he had his surgery until today, and what our plan is with him," McCoy said. "And will let you know when we make a decision."
Asked if he had suffered any setbacks, McCoy did not answer the question specifically, only saying that Clary is working every day to get better.