LAKE FOREST, Ill. -- Chicago Bears defensive tackle Dusty Dvoracek will go on season-ending injured reserve because of a torn anterior cruciate ligament in his right knee.
Dvoracek underwent arthroscopic surgery Friday after initial tests were inconclusive about damage to his right knee, which he injured during Saturday's preseason game against the New York Giants.
Dvoracek, a fourth-round draft pick in 2006, went on injured reserve as a rookie because of a foot ailment he suffered during the preseason. He tore his left anterior cruciate ligament in the 2007 season opener and last year played 12 games before going out for the year with a torn biceps.
Dvoracek led the Bears' defensive line with 40 tackles at the time of his injury last season.
"Right off the top of my head, I haven't seen a lot of players go through that," Bears coach Lovie Smith said. "Guys deal with injuries always. As much as anything, with Dusty, though, it's one thing to have injuries and they continue to linger. These are different things.
"He's getting things fixed. So really, once he comes back from this, he should be as good as ever, so he should still have all of his options open."
Dvoracek, who is in the final season of a four-year contract, should be able to continue workouts in seven to 10 months.
Dvoracek had been competing with second-year pro Marcus Harrison for the Bears' starting nose tackle job. The two are backed up by third-year pro Matt Toeaina, whose chances of making the roster have now improved.
"I hate to see this happen to Dusty again, but I've definitely got to take advantage of the opportunity," Toeaina said.
"My opportunities have been limited, but like they say, you can't count your (practice) reps; you've got to make your reps count," Toeaina said.
Toeaina credited new defensive line coach Rod Marinelli with drastically improving his play this season.
"With coach Marinelli, we've actually learned a lot more when he got here," Toeaina said. "So I feel like what I knew before wasn't much, and now thanks to coach Marinelli, I have a lot of knowledge of the opposition."
Notes: DE Israel Idonije missed Friday's practice with a sore hamstring, and his status for Sunday's game against the Denver Broncos is uncertain. ... DE Alex Brown, who missed Thursday's practice with a sore hamstring, returned for Friday's workout. ... The Bears have a quick turnaround after Sunday's game, with a Thursday preseason finale at Soldier Field against the Cleveland Browns. As a result, the team will have only one practice next week before playing the game.
Copyright 2009 by The Associated Press