Cardinals defensive end Kyle Vanden Bosch, who blew out his right knee in 2001, suffered torn ligaments to his left knee in the first half of the Cardinals exhibition game against the Chargers.

The injury could be season-ending, but the team won't know until Monday.

"We find out what the prognosis is Monday and if he's not there, I'm just sick,'' Cardinals coach Dave McGinnis said. "The time he laid out there on the grass, you knew there was something wrong.''

Vanden Bosch, a second-round choice in 2001, was just starting to feel more comfortable playing on his reconstructed right knee and had made a transition from right defensive end to the left side. Vanden Bosch suffered the knee injury during the second quarter of the game and stayed on the field for a couple of minutes while trainers worked on the knee.

Vanden Bosch was able to walk off the field without assistance, but he was immediately taken to the locker room for X-rays. It is not initially known if the injury is season-ending, but it would appear to be serious.

"There is nothing I can do about it and nothing he can do about it,'' McGinnis said. "He'll take an MRI Monday. You know, that's the chances you take when you line up and play the game.''

The Cardinals know it will be hard replacing their starting left end if he's out for the season.

"Still, we've got to play, but if you are asking me if there is anybody out there on the street as good as Kyle Vanden Bosch, there isn't,'' McGinnis said.

John Clayton is a senior writer for ESPN.com.