Holdman finished second on the team with 145 tackles in 2001. The Bears matched a four-year, $12 million offer sheet the restricted free agent had signed with the Kansas City Chiefs. He hasn't been put on injured reserve yet, but the move will be completed in the coming days.
A similar injury to the linebacker's left knee forced him to miss the final six games of the 2000 season. Holdman's rehabilitation is expected to take three months meaning he should recover fully for the 2003 season.
However, the immediate impact is the Bears are now without four starters on defense.
Dick Jauron accepts the fact that injuries are part of the game and can't be used as an excuse.
"I feel badly for the team, I feel badly for the player, but the team goes on," Jauron said. "It really is part of our business and you have to go on and if you get demoralized, it's certainly not going to help you play. You have to stay up and you have to work hard and prepare and go out and play the next week."
Phillip Daniels practiced Monday for the first time since spraining his left ankle, but probably won't play against Green Bay. R.W. McQuarters' left knee is still bothering him and according to him will not return until the Detroit game on Oct. 20. Meaning Chicago could go into their Monday Night match-up with Green severally short handed.
Mike Caldwell, who has started 46 games in 10 seasons including 16 last year, will replace Holdman.
"Mike's a veteran, he knows how to play, he understand the speed of the game in the National Football League," Jauron said. "He's seen a lot of formations, adjustments, things of that nature. He's a very smart player, so he brings experience to the table for us and he's been a successful and productive player in the past.
"Unfortunately, the reason why we got him was because we thought he was a high quality backup in case something happened, hoping that nothing would happen, but we've lost a starter and Mike has to step right up."
When Holdman went down against Buffalo Caldwell pulled double duty at weakside linebacker and on kick coverage. Despite having five tackles Caldwell cost the Bears with two mistakes on special teams a 15-yard facemask penalty and holding call on a kickoff return.
Jauron said there is a good chance the team will look at available linebackers on the market, but for the present the defense must be able to play as a unit. Something that is hard to do with six new faces from the end of last season when you include the loss of Tony Parrish and Walt Harris to free agency and injuries to Holdman, Daniels, McQuarters and Ted Washington.
"There's no doubt the longer you play together the better off you're going to be, the more you know each other, where you fit, all those positive things," Jauron said. "(But) there's nothing we can do about the injuries. We just have to find ways to win games."