Looks like the knock on the head wasn't serious, and we can all let our breath out regarding Pablo Mastroeni. The Colorado Rapids captain got hit in the head against the Columbus Crew and was removed from the game immediately for fears of him getting another concussion. He was sidelined for the entire playoffs last season after getting a concussion against Real Salt Lake.
Fortunately, the Rapids tweeted earlier today that Pablo was training again, so I think we can assume that he's all right to play this Sunday against the Philadelphia Union. Also included in the tweet was Hunter Freeman, who was forced to miss the first game of the year - not that they would have used him since the defense stayed good the entire match - was training as well, which should put another notch into the defensive depth.
The healthier this team is, the better. Good to see everyone ready to play, especially Mastroeni. Concussions have ended careers before and we would all rather see Pablo retire when he's ready, not when the doctor tells him to.