EAST RUTHERFORD, N.J. (AP) New York Giants starting middle linebacker Jon Beason sprained his left knee in the second quarter against the Jacksonville Jaguars on Saturday night and did not return.
Beason, one of the leaders of the defense, played four games last season before going on injured reserve with a foot injury.
Neither coach Tom Coughlin nor teammates knew the severity of the injury.
''I have no idea, I haven't had a chance to talk to Jon about it,'' fellow linebacker J.T. Thomas said after the Giants 22-12 win. ''Everyone here knows Jon is an essential part of our defense. He's our leader. He's the guy we look up to. Of course it affects our leadership and our style of play.''
Giants rookie Justin Currie broke his right ankle and fellow safety Bennett Jackson sprained a knee. Backup linebackers Mark Herzlich (concussion) and Tony Johnson (knee) left the game.
Currie, a special teams hopeful who had been getting snaps with the second-team defense, went down while covering a kickoff. He was carted off the field in considerable pain. Jackson was hurt making a tackle late in the game.
New York lost rookie safety Mykkele Thompson last week with an Achilles tendon injury. Safeties Cooper Taylor (toe) and Landon Collins (knee) did not play.
''It's amazing how these injuries are going,'' Coughlin said. ''We had safety earmarked as a problem position, and we got two guys hurt tonight.''
The Jaguars also had a couple of injuries. Backup offensive tackle Josh Wells dislocated a thumb and receiver Arrelious Benn broke a clavicle. Linebacker LaRoy Reynolds sprained a knee and receiver Damian Copeland dislocated a shoulder. Cornerback Demetrius McCray had a leg contusion.
Both teams were banged-up coming into the game.
New York was without starting cornerback Prince Amukamara (groin) and receivers Victor Cruz (calf) and Rueben Randle (knee).
Jacksonville did not have TE Julius Thomas (broken hand), receiver Marqise Lee (hamstring) and rookie running back T.J. Yeldon (sprained finger).
AP NFL website: www.pro32.ap.org and AP NFL Twitter feed: www.twitter.com/AP-NFL