While the Phillies haven't had as many injuries this year as last (22 in 2010), they still have some key veterans that could get injured in, or just before, the postseason.
Jimmy Rollins, the Phillies shortstop, has gotten injured multiple times in the past. Chase Utley was out for the first two months of the season. Placido Polanco has been on and off the DL multiple times.
Roy Oswalt just returned from an injury and often has back troubles. Brad Lidge recently returned from an injury, but has been on the DL multiple times. Ryan Madson just returned from the Disabled List, and Jose Contreras has been out since June.
As you can see, multiple Phillies have been injured at one time or another and there is a chance several could get injured again.
For now, let's just hope that there aren't any more injuries for a long while.