Kansas City Royals ace left-hander Cole Ragans will undergo testing on his left groin after sustaining the injury and leaving Thursday’s start against the Colorado Rockies after three innings.

Ragans had trouble getting loose in the bullpen prior to the game and the soreness continued through his 62-pitch outing.

“Cole was not 100 percent,” Royals catcher Salvador Perez said after the team’s 7-4 victory in the first game of a doubleheader. “I could tell from the bullpen he was not right.”

The 2024 All-Star struggled throughout and gave up four runs on three hits and two walks. He served up two homers and struck out four.

Kansas City manager Matt Quatraro said Ragans felt the groin tighten up between the third and fourth innings. The manager then replaced Ragans with lefty Angel Zerpa.

“If he’s not comfortable pushing off, you’re seeing him cut some stuff off, which makes sense, based on most of those misses,” Quatraro said. “Just probably wasn’t getting through it.”

Ragans is 1-1 with a 4.40 ERA in six starts this season. He has struck out 46 batters in just 30 2/3 innings.

Last season, Ragans went 11-9 with a 3.14 ERA in 32 starts while making his first All-Star Game. He finished second in the American League with 223 strikeouts and finished fourth in AL Cy Young Award balloting.