Robert Griffin III has dislocated ankle

— -- Robert Griffin III has a dislocated left ankle, an injury that will sideline the Washington Redskins star quarterback indefinitely.

Redskins coach Jay Gruden announced the diagnosis following Washington's 41-10 victory over the Jacksonville Jaguars.

Griffin suffered the injury while rolling to his right toward the sideline in the first quarter. Although he was not touched on the play, Griffin fell awkwardly out of bounds and was carted to the locker room.

"It's an excruciating pain," Griffin said. "Anytime you look at your ankle and it's going in a strange direction, you don't want to get up."

After his leg was placed in a splint, Griffin waved, saluted and gave a thumbs-up signal to the crowd as he was carted along the sideline and down the players' tunnel.

"Moments like this," Griffin said, "you just have to keep the faith."

Griffin was replaced by Kirk Cousins, who passed for 250 yards and two touchdowns in the victory.

"[Cousins] has handled being a backup like a pro," Gruden said. "He's waited patiently, and now his time is going to come to really take this thing and run with it."

Redskins receiver DeSean Jackson also left the game in the first quarter with a shoulder injury and did not return. He was diagnosed with an AC joint sprain and is considered day to day.

"This one was a little vicious, the pain right on the bone and things like that," Jackson said. "So I'm day-to-day."

Griffin is less than two years removed from reconstructive knee surgery and visibly struggled in his recovery from the operation last season.

The Associated Press contributed to this report.