(Reuters) - Rookie Washington Redskins' quarterback Robert Griffin III will not start Sunday's game against the Cleveland Browns after failing to overcome a knee sprain.

"The decision was not my own..." Griffin tweeted on Saturday after failing a medical check. "But I will be there for my team!!! In every way I possibly can."

The Redskins are expected to start rookie quarterback Kirk Cousins in his place. Cousins, a fourth round pick out of Michigan State, will be making his first career start.

Washington (7-6) are second in the NFC East, a game behind the New York Giants (8-5) in the division and the Chicago Bears (8-5) and Seattle Seahawks (8-5) in the wild card race with three games to play.

(Reporting by Ben Everill in Los Angeles; Editing by Greg Stutchbury)