Pittsburgh Steelers quarterback Ben Roethlisberger is rated as "questionable" for Sunday's crucial National Football League game against the Baltimore Ravens following his shoulder sprain against the Kansas City Chiefs.
The 30-year-old was replaced by Byron Leftwich after being injured during the second half of Monday night's game and eft the stadium with his arm in a sling.
A scan afterwards revealed he had suffered a sprain to the joint between the collarbone and the sternum, which would restrict movement in his throwing arm.
Steelers coach Mike Tomlin admitted the injury put a doubt over whether Roethlisberger would be able to feature this weekend.
"He is being evaluated," he said.
"Obviously this injury puts his participation in the questionable category for this week. I will have more information as I get it, as the week unfolds."
The loss of Roethlisberger would be a major blow for the Steelers, who trail the Ravens in the AFC North.
After facing the Ravens at home, Pittsburgh have another divisional game at the Cleveland Browns before travelling to Baltimore for the return game on December 2.
Meanwhile the Chicago Bears have brought back veteran quarterback Josh McCown following Jay Cutler's concussion.
McCown, who began last season as a high-school football coach in North Carolina and ended it playing for the Bears, has been brought in as backup for the role once again.
"We always have to look ahead for situations like that," Bears coach Lovie Smith said.
"Every available quarterback is an option for us if we felt like we needed to go in that direction.
"He (McCown) has played good football for us. We're familiar with him."
McCown, 33, appeared in three games for Chicago last season and made two starts, completing 35 of 55 passes for 414 yards with two touchdowns and four interceptions.
The nine-year league veteran re-signed with the Bears in March and spent the entire off-season with them before being released on Aug. 31.
Cutler and Campbell are the only two other quarterbacks on Chicago's 53-man roster.
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