Cleveland Browns head coach Pat Shurmur announced Friday that third-string quarterback Thaddeus Lewis will start the season finale at Pittsburgh.

Fellow quarterbacks Brandon Weeden and Colt McCoy injured their right shoulders last week at Denver. They missed practice all week.

Lewis' first NFL start will come against a Steelers defense that is ranked No. 1 overall in the NFL. Josh Johnson, who signed with the Browns earlier this week, will be his backup.

Shurmur also said that rookie running back Trent Richardson will miss Sunday's game with a sprained ankle. He needed just 50 yards to reach 1,000 for the season. Montario Hardesty will start in Richardson's place.