The team also officially announced the signings of receivers Breshad Perriman and Michael Floyd.
Kelley injured a toe in Sunday's loss to the Indianapolis Colts. Coach Jay Gruden said Monday that Kelley might require surgery and would be sidelined at least four weeks. Now that he's on injured reserve, Kelley can't come off for at least eight games.
The Redskins also have running backs Derrius Guice and Byron Marshall on injured reserve. Guice is lost for the year with a torn ACL, but Marshall, who sprained a knee, should be ready to return after the eighth game.
Kelley carried four times for 8 yards in two games. He also played fullback on occasion when the Redskins used I-formation.