As you can see and hear in this SportsCenter video from Adam Schefter, Washington Redskins rookie quarterback Robert Griffin III has been cleared to practice today and the team is optimistic he'll play Sunday. It's absolutely a good sign, and reports that Griffin has been symptom-free since he had to leave the game with a concussion Sunday are encouraging as well.
It's worth remembering, however, that the NFL's concussion protocols are a week-long process for a reason. Concussions are a tricky and serious business, and just because a guy is symptom-free on Tuesday doesn't mean symptoms can't show up again Wednesday or Thursday. The league is watching these situations very closely in light of the hundreds of former players suing them over alleged negligence regarding head injuries, and Griffin must be cleared by an independent neurologist before he can return to game action. The fact that he's been cleared by the league to practice is a good first step. It's just not the last one.