CHICAGO (AP) - Taj Gibson is expected to miss at least two weeks with a sprained left knee, forcing the Chicago Bulls to play without one of their key reserves at a pivotal point in the season.
Gibson stepped on the foot of Oklahoma City guard Reggie Jackson in the fourth quarter of Sunday's 102-72 loss to the Thunder and knew something wasn't right almost immediately.
"The first thing I did was grab my knee," he said. "I was in shock because I felt great. I went up for a regular shot block and I came down and it just gave way."
Gibson had an MRI and was diagnosed with a sprained medial collateral ligament. He said doctors are planning to take another look to make sure there are no small tears.
It could be a crippling blow for the Bulls, who have been without Derrick Rose all season while the 2011 NBA MVP recovers from major left knee surgery. Gibson, Carlos Boozer and Joakim Noah have played almost all the post minutes for Chicago, and Gibson's injury means coach Tom Thibodeau likely will have to give more minutes to seldom-used center Nazr Mohammed.
"Everybody in that locker room is capable of playing well, so all you have to do is go out there and do your job," Thibodeau said before the Bulls hosted Cleveland on Tuesday night.
Chicago did get one piece of positive news before facing the Cavaliers, with point guard Kirk Hinrich returning to the lineup. Hinrich had missed 10 of the last 11 games due to a lingering right elbow problem.
Replacing Gibson will be no easy task for Thibodeau, who had deftly coached the Bulls to a 32-24 record heading into the matchup with the Cavs. The 6-foot-9 Gibson is a rugged defender who is averaging 7.7 points and 5.4 rebounds.
Gibson said the injury gave him more sympathy for Rose, who hurt his knee in the playoffs last season.
"The things he is doing now coming back from that is hard," Gibson said.
AP freelance writer Patrick Rose contributed to this report.
Jay Cohen can be reached at http://www.twitter.com/jcohenap