Right-hander Taijuan Walker had been a sort of safety-net-in-waiting this season for the Diamondbacks, a potentially valuable rotation piece whose steady recovery from Tommy John surgery gave them peace of mind about the state of their starting pitching.
All of that changed this week. Walker left his rehab start on Wednesday at Salt River Fields with right shoulder discomfort. He was diagnosed with a capsule sprain and received a platelet-rich plasma injection, manager Torey Lovullo said. Walker will not throw again for six weeks, a delay that likely pushes his return from the injured list back to August at the earliest.