Only moments after his solid, albeit brief, NFL debut last week, rookie quarterback Robert Griffin III had another new experience: His first foot-in-mouth news conference as the face of the Washington Redskins.

Griffin said practice was tougher than a 7-6 victory over the Buffalo Bills, providing bulletin-board material for the Redskins’ remaining opponents. Griffin wasn’t being cocky or disrespecting the Bills, his teammates insist, but they acknowledge he erred in expressing the widely held belief among players that training camp is more challenging than preseason games.

And in his most insensitive word choice of the evening, Griffin thanked Redskins veterans for teaching him “what to pay attention to in the games. Because a lot of times, once you do get out [on the field], you can get completely out of the game and just start doing retarded or ridiculous things.” Using “retarded” to describe something awkward should happen about as often as Hitler’s name is invoked when commenting on someone’s shortcomings. Just don’t do it.

“You know, I just kind of cringed when I heard” about Griffin’s rough news conference, said wide receiver Santana Moss, among a group of Redskins veterans who counsel Griffin about how to succeed in professional sports’ toughest league.

“He’s a good person and he has good intentions. He didn’t mean to hurt anyone, or hurt the team, with what he said. He just worded some things wrong, which is gonna happen. We’re excited to have him here, the fans are excited and everybody should be. But, man, this ain’t gonna happen overnight.”

Griffin’s off-field missteps immediately following his effective 14-play performance in the Redskins’ preseason opener underscore something that has been lost in the hype surrounding Griffin: The 22-year-old has a lot to learn.

Coach Mike Shanahan is qualified to raise Griffin correctly, having mentored other uniquely talented passers during his career. And team leaders such as Moss and inside linebacker London Fletcher are committed to helping the Heisman Trophy winner become an NFL superstar (not coincidentally, Griffin dresses next to Fletcher, the 15-year veteran, in the locker room). The process, however, is only starting — and it definitely won’t always be a smooth one.

Even with little on which to judge Griffin so far, it’s already clear he possesses both the smarts and the physical tools to eventually become everything the Redskins and their fans want him to be, “but there are going to be growing pains because that’s the nature of the position,” Shanahan said.

That doesn’t mean the boss didn’t notice Griffin’s verbal slips. It’s just that he isn’t surprised or concerned about them. “What Robert has done is, he has given himself every chance to be successful because of the way he works . . . the way he handles himself,” Shanahan said. “Am I going to worry every time Robert makes a mistake in something he does [on the field] or says? No. Because I know what goes into this. The only way you get better is through repetition” in doing everything that goes into being a starting quarterback. That includes not inserting foot into mouth.