(John McDonnell/The Washington Post) (John McDonnell/The Washington Post)

As he returns from offseason knee surgery, quarterback Robert Griffin III will have to protect himself better by learning how to slide at the end of a run and throw the ball away to avoid hits, Redskins Coach Mike Shanahan said Wednesday.

“You can’t take shots consistently,” Shanahan said at the annual league meeting in Phoenix.

Shanahan, speaking to reporters at the NFC coaches’ breakfast, reiterated that Griffin is ahead of schedule in his recovery from surgery in January for tears of his right anterior cruciate and lateral collateral ligaments. Shanahan said that Griffin is spending six to eight hours per day on his rehabilitation.. He added that “you’re always optimistic” when he was asked about Griffin’s potential readiness for the regular season opener in September.

But Shanahan also acknowledged he does not know that Griffin will be ready.

“If hard work has anything to do with it, he’ll be ready,” Shanahan said.

Griffin must guard against pushing himself so hard that he suffers a setback, Shanahan said. He conceded he will have some thoughts in the back of his mind about what happened in the past whenever Griffin tells him that he’s able to stay in a game while hurting.

Even so, Shanahan continued to maintain that Griffin belonged on the field during the Redskins’ playoff loss to the Seattle Seahawks, a game that Griffin was unable to finish because of his knee injury. He underwent surgery days later.

“You rely on your doctors and you rely on the player… He earned the right to stay in the game. He earned the right. And that’s why he was in there,” Shanahan said.

Shanahan said he expects orthopedist James Andrews to be on the Redskins’ sideline during games in the future, as he was last season.

The Redskins’ offensive system, which includes option plays and runs by Griffin, helps to keep a quarterback healthy by keeping the defense off balance and slowing down the pass rush, Shanahan said. He seemed to dismiss the possibility that the system will be overhauled after Griffin’s injury. He added, however, that the Redskins don’t actually have to use Griffin as a runner to keep defenses honest.

“You don’t have to run it,” Shanahan said, acknowledging that defenses will make offseason adjustments to offenses that feature quarterbacks who are running threats. “But they have to prepare for it.”