Mariners right-hander Taijuan Walker had to be scratched from what was supposed to be his final minor league rehab start Tuesday at Triple-A Tacoma and he headed to Seattle on Wednesday for tests.
The MRI results are in, according to Bob Dutton of the Tacoma News Tribune, and Walker has been diagnosed with a right shoulder impingement. He will be shut down from throwing for two weeks, and can now probably be ruled out through at least mid-May.
Walker was supposed to open the 2014 season as a member of Seattle’s starting rotation, but he battled shoulder problems all spring and landed on the 15-day disabled list before Opening Day.
The 21-year-old top pitching prospect registered an impressive 2.93 ERA, 1.196 WHIP, and 10.2 K/9 in 141 1/3 innings last season between the Double-A and Triple-A levels. He then made his MLB debut August 30.