Four days after suffering the first concussion of his NFL career, Robert Griffin III said he's learning to walk the fine line between making a play and making sure he avoids serious injury.It doesnt make you less aggressive, Griffin said of the shoulder-to-helmet hit that knocked him from Sundays 24-17 loss to the Falcons. The one thing I learned is, I cant do that to my team, to the fans, or to my family, because life is more important than the game of football. Getting hit in the head affects us down the road. I have to make sure I limit that.In retrospect, Griffin said he should have slid earlier, run out of bounds or thrown the ball away instead of attempting to extend the play.I tried to get down, he said. If I would have slid a half-second earlier, I would have been safe. But I tried to get down too late and linebacker Sean Weatherspoon had already launched. At that point, it was just a matter of absorbing the hit and I absorbed it the wrong way.In the future, he added, looking back on it, hindsight is 2020, I would have either thrown it away or got out of bounds.Griffin was limited in practice Wednesday, according to Coach Mike Shanahan. Griffin, however, said he was sharp in drills and expects to suit up Sunday against the Vikings.He has not been cleared for contact yet and there's no timetable for that to happen. Griffin will be evaluated by doctors after each practice. Shanahan said clearance could come as late as Sunday morning.I felt sharp, Griffin said. I felt good. No symptoms of a concussion or anything like that. No dizziness or being off balance. Im not just saying that.Then he cracked: You always feel like youre going to be ready to go.The only symptom that I do have is irritability, because they keep asking me the same questions.Although the experience may have rattled the quarterback a little, it certainly didnt affect his sense of humor.Asked how he intends to ensure he doesnt absorb a similar hit in the future, Griffin joked: I ran out of bounds today in practice and imitated a slide, and got a huge cheer from the team.Its not about being soft, Griffin added. I dont have anything to prove to anybody. Everyone knows Im a tough guy. I dont have anything to prove. If you have to live to play another down, you live to play another down.In addition to teaching him a valuable lesson about football, it seems the ordeal also helped put things into perspective for the rookie. Its a learning experience for me, he said. You appreciate things a lot more after something happens. My head, my future outside of football, my life, is more important than trying to get that touchdown on third and four. You have to know when to run out of bounds.