LAKE FOREST, Ill. --Their eight-game winning streak and top-rated defense were shoved to the background Wednesday when the Chicago Bears moved Rex Grossman up the depth chart to No. 2 quarterback behind rookie starter Kyle Orton.

Grossman, the starter before breaking his ankle in a preseason game Aug. 12, has been the emergency third quarterback the past two weeks. Now he's closer to replacing Orton, who's struggling and has a quarterback rating of 60.2.

Deemed healthy, Grossman also got limited practice time Wednesday with the first unit as the Bears (9-3) prepared for Sunday's game in Pittsburgh.

"Obviously I want to play," Grossman said. "There's no one in this locker room that doesn't want to play. At the same time I don't want to be a distraction to the team, I'm just here trying to do the best I can do. Whatever they tell me to do, I'm going to do.

"I'm physically able to do everything that I need to do to play. ... I just know, it's pretty obvious we need to get better in the passing game."

Grossman underwent surgery after breaking his ankle in the second preseason game at St. Louis -- his second major injury in as many seasons.

Orton has been the starter during the team's longest winning streak in 20 years, one built on defense and a running game.

He connected on just 6 of 17 passes last week for 68 yards in a victory over Green Bay.