ARLINGTON, Texas -- Yu Darvish was placed on the 15-day disabled list Monday with shoulder discomfort, but two MRIs showed no structural issues for the Texas Rangers pitcher who has made only three starts since returning from major elbow surgery.

Texas had already decided to skip Darvish's scheduled start at Oakland on Monday, when the right-hander from Japan was instead in Texas. Darvish had an MRI on his shoulder and another on his neck before being examined by team physician Dr. Keith Meister.

Darvish last pitched on Wednesday, when he went five innings against Houston. He said after the early exit that tightness in his neck caused tightness in his shoulder, and then cut short a bullpen session Saturday after experiencing the same symptoms.

The team said he will receive treatment until he is ready to begin throwing again.

"There were no acute findings on either MRI, which is a good thing, meaning that there was nothing structural that was cause for concern," general manager Jon Daniels said in Oakland, California. "That said, Yu continues to have discomfort in that area, and so we're going to place him on the DL to give him more time to recover."

Daniels said after consulting with Meister that it is not unusual for someone coming back from surgery to have some discomfort in another area.

The DL move was retroactive to Thursday, the day after Darvish's last start.

Yu Darvish has been placed on the disabled list with tightness in his neck and shoulder. AP Photo

Texas also activated outfielder Shin-Soo Choo from the 15-day disabled list and recalled left-hander Alex Claudio from Triple-A Round Rock. Outfielder Jared Hoying was optioned to Round Rock.

Darvish (2-0, 2.87 ERA) has pitched 15⅔ innings since returning from the 60-day DL on May 28. He had Tommy John surgery on his elbow on March 17, 2015, and missed all of last season. He made five rehab starts in the minors last month before rejoining the Rangers.

Daniels said the Rangers will treat Darvish cautiously until the discomfort subsides, and they don't have a time frame for when he will start throwing again.

"We haven't put a timeline on it. He'll get some treatment, some soft tissue work and we'll go based on his feeling," the GM said. "I doubt he's going to be throwing the next day or so, but there's no doctor-prescribed timetable. He'll go off of how he's feeling."