Darvish told the team about the stiffness after waking up late Tuesday morning. He received treatment and reported some improvement, according to club officials, but is still experiencing some stiffness.
Scott Baker started against his former team in Darvish's place. Baker gave up six runs on eight hits in six innings in a 7-2 loss to Detroit on Friday. He then was moved to the bullpen as the long man with Joe Saunders taking his place in the rotation.
The Rangers said a precautionary MRI was "unremarkable" and looked similar to MRIs in spring training. Darvish's next start has yet to be determined, the team said.
Darvish indicated to the team that the symptoms are similar to what he felt in mid-March during spring training, which forced him to the disabled list to start the season.
He made his first start April 6 and hadn't missed one until Tuesday night.
Darvish, 27, was the runner-up in the American League Cy Young balloting in 2013 and has started this season well. He is 4-2 with a 2.35 ERA in nine starts. He is fourth in the AL in ERA and seventh in strikeouts (71).
The injuries continue to mount for the Rangers, as the Darvish news comes the same day Prince Fielder had spinal fusion surgery in Dallas. The Rangers have had 17 disabled list stints this season, the most in the majors.