Phillies' Taijuan Walker: Out with shoulder impingement

Walker was diagnosed with a right shoulder impingement Sunday and will start the season on the injured list, Todd Zolecki of MLB.com reports.

The veteran right-hander experienced some discomfort while prepping for a bullpen session Saturday, and he won't be available to begin the regular season. Walker will rest for an undisclosed period before attempting to restart his throwing program, so he seems likely to spend more than the 15-day minimum on the injured list. Spencer Turnbull is poised to claim the open spot in Philadelphia's starting rotation.