We feared the worst for Pablo Mastroeni after he sustained a head injury only 74 minutes into the MLS season against the Columbus Crew. Unfortunately, it doesn't look good for the Colorado Rapids captain. He originally suffered a concussion last year against Real Salt Lake in the season finale, an injury that knocked him out of the playoffs but seemed to be better by the time 2012 rolled around.

Unfortunately, it looks like we'll have well over a month before Pablo is ready to play again, and his career might be in jeopardy if the head injury continues to torment him. In a league where concussions are suddenly priority number one, a concussion and symptoms continuing from one are seen as no joke. Martin Rivero took his attacking midfield spot on Sunday against the Chicago Fire and played well.

Is this the end for Pablo? At the very least, we all would like to see Mastroeni play a few more games in the burgundy and white before he calls it quits on what has been a fruitful career in Major League Soccer.