Mike Shanahan on Robert Griffin III: “There’s a lot of areas that you grow in. . . The one thing he is going to have to learn how to do is how to slide, how to throw the football away, how to protect himself. . .You can’t take shots consistently in the National Football League.” (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, Washington Redskins Coach Mike Shanahan said Wednesday.

“You’re always going to grow from your first year to your second year,” Shanahan said on the final day of the annual NFL meeting. “There’s a lot of areas that you grow in. . . . The one thing he is going to have to learn how to do is how to slide, how to throw the football away, how to protect himself. . . . You can’t take shots consistently in the National Football League.”

Shanahan, speaking to reporters at the NFC coaches’ breakfast, said again that Griffin is ahead of schedule in his recovery from surgery in January on tears of the anterior cruciate and lateral collateral ligaments in his right knee. Griffin is spending six to eight hours per day on his rehabilitation, Shanahan said.

Asked about Griffin’s potential readiness for the regular season opener in September, Shanahan added: “You’re always optimistic.”

But Shanahan also acknowledged he does not know that Griffin will be ready to play in the season opener, calling it “kind of ludicrous” to try to assess at this point.

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“He’s a worker,” Shanahan said. “He’s working out six, seven, eight hours a day. He’s doing everything he possibly can to get himself ready. If hard work has anything to do with it, he’ll be ready. But it’s a process. I can’t tell you anything until July. If I did, I’d be kidding you.”

Griffin must guard against pushing himself so hard that he suffers a setback, Shanahan said. He also conceded that he will have some thoughts in the back of his mind about his decision to keep Griffin on the field whenever his young quarterback tells him he is able to stay in a game while hurting.

But 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 a knee injury. He underwent surgery days later.

“I don’t get a chance to evaluate people on the sideline during a game. I’m watching it, making calls, making substitutions,” Shanahan said “. . . So what you do is 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 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 keep a quarterback healthy by throwing the defense off balance and slowing the pass rush, said Shanahan, who appeared to dismiss the possibility that the system will be overhauled after Griffin’s injury. He added that the Redskins don’t actually have to use Griffin as a runner to keep defenses honest.

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