"It still didn't feel right," Locke said. "I didn't see any point to keep throwing. So I stopped."
While the Pirates traveled to Port Charlotte to meet the Rays, Locke planned to consult with the team's training staff, and possibly even a doctor to get an updated diagnosis and recommended course of action.
This is a disappointing setback for the 2013 National League All-Star, whose first and only exhibition outing had been encouraging regarding his prospects of bouncing back from a disappointing second half of the season. Facing the Yankees on Feb. 27, Locke had pitched one-hit shutout ball for two innings, with one strikeout.
Another red flag: Locke could be affected if, even after he resumes pitching, the tender right side causes him to cut back on his normal workout routine. Reducing his between-starts regimen following a lower-back issue was partly blamed for his 2-5, 6.52 ERA performance after the All-Star break.
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.