NL manager Bruce Bochy will name a replacement on his All-Star staff for Locke, who will still attend festivities in New York and at Citi Field on a non-participatory basis.
The young lefty already has a reserved spot in the post-All-Star break rotation -- he is scheduled to pitch on Sunday, July 21, in Cincinnati -- so this appears to be a minor timeout facilitated by the four-day All-Star break.
"Really, we could not have had a better time to take care of that type of physical issue," said manager Clint Hurdle.
Locke reported the discomfort after a seven-inning outing on Monday against Oakland. He went through his regular bullpen session on Friday, when the tightness continued.
"He felt just a little off," Hurdle said. "But he was on the mound [Friday], so we know he's close. With the four additional days [off for the break], next Sunday he will be in a good place."
General manager Neal Huntington, trainer Todd Tomczyk, Hurdle and Locke took a meeting before deciding on their course of action.
"Jeff said, 'If push came to shove, I could probably do it. But I think it'd be selfish of me to go out there and pitch.' So that's where we are," Hurdle said.
The manager also announced his post-break rotation around Locke: Francisco Liriano and A.J. Burnett before him, in the first two games against the Reds, and Charlie Morton and Cole after him, in Washington against the Nationals.
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.