indeed had a "mild" concussion and has been cleared to resume physical activity. He is likely to play sometime next week when the Phillies come back to Philadelphia.
Like all concussions, it could turn out to be nothing or it could be very serious: Chase Utley was removed from Wednesday night's game against the Braves after getting hit in the head by a pitch. The early word is that Utley suffered a "mild" concussion (as if there really are mild concussions), and will miss the next few games. He will not travel to Milwaukee with the rest of the team and will instead stay in Philadelphia for further testing.
When you are coasting to the best record in baseball, minor injuries in the beginning of September aren't a big deal. When the injury is a concussion, though, it's always a concern. Given the streaky nature of the Phillies offense, they need to have all bats on hand come October. Let's hope Utley sits out for a few days, clears the cobwebs and comes back rested and ready for another deep playoff run.