Right-hander Jacob deGrom was diagnosed with a tear in his right ulnar collateral ligament and will undergo Tommy John surgery, the Texas Rangers announced Tuesday.

The Rangers gave the injury-prone deGrom a five-year, $185 million contract in free agency last December and got six starts out of him before he needed to be placed on the injured list with right elbow inflammation.

deGrom, who turns 35 this month, was transferred to the 60-day injured list on Monday as the Rangers said he would undergo another MRI exam and additional testing. That MRI revealed the ligament tear.

The surgery will take place next week and sideline deGrom at least 12 months.

“This stinks,” deGrom told reporters Tuesday. “It’s not ideal. But at least we know what it is now. I want to get it fixed and will set a goal to be back before the end of next year.”

A two-time National League Cy Young Award winner with the New York Mets, deGrom has a history of arm woes in recent seasons. He made just 38 starts and pitched 224 1/3 total innings over the past three seasons with the Mets before departing as a free agent.

In his first six starts with Texas, deGrom went 2-0 with a 2.67 ERA and had 45 strikeouts to just four walks in 30 1/3 innings.

deGrom had Tommy John surgery once before, in October 2010 while he was a prospect in the Mets organization.

–Field Level Media