CLEVELAND -- Carlos Carrasco has filled in admirably as the Indians' de facto ace this month while Corey Kluber has been sidelined with a back issue. 
Cleveland is hoping that its rotation situation does not became more complicated after Carrasco encountered an injury of his own on Monday night.
In the fourth inning of Monday's 8-7 win over the Rays, Carrasco exited an ineffective outing with head athletic trainer James Quinlan, following a discussion on the mound with manager Terry Francona. The Indians announced that the right-hander exited the contest with left pectoral tightness.

"The left pec area was tight. I don't think anybody thinks it's anything more than that," Francona said. "He wasn't letting it go, and you start to worry a little bit. When I went out there, finally he kind of said, 'Yeah, it's tight.' So, we got him out.
"We'll certainly look at him more [Tuesday]. We'll have a much better read. But it's hopefully, maybe a couple days could remedy that. We'll see."
Carrasco entered the night with a 1.86 ERA, but allowed at least one run in each inning against Tampa Bay. When his outing was complete, the right-hander was charged with five runs on six hits, ending with six strikeouts and three walks. Carrasco had only two walks in his previous four starts combined.
One red flag was found in Carrasco's pitch velocity as his start against the Rays progressed. Per Statcast™, the righty averaged 95 mph on 10 fastballs in the first inning, but his average pitch speed on his four-seamer dropped to 92.3 mph (13 pitches) in the fourth inning. Carrasco was averaging 94 mph with his four-seamer (263 pitches) on the season, entering Monday.
"I was not able to finish my pitches, then my velo went down," Carrasco said. "I'm just waiting until tomorrow to see what is going on and we'll go from there."
During Spring Training, Carrasco missed 10 days of Cactus League play due to right elbow inflammation and was limited to 15 spring innings before the start of the season. Carrasco's disjointed preseason did not deter him from enjoying a strong start to the season.
 After working with a limited pitch count in his first start of the year, Carrasco logged at least six innings in each of his six starts prior to Monday's game. He had not allowed more than three runs in an outing, ranking fourth in the American League in ERA and third in opponents' batting average (.177), entering Monday.
At the moment, Carrasco was atop the Indians' rotation, with Danny Salazar, Josh Tomlin and Trevor Bauer following in the next three spots. Right-hander Mike Clevinger was promoted from Triple-A Columbus and has been filling in for Kluber since the ace was shelved on May 2 with a lower-back strain. Kluber resumed throwing off a mound on Monday, but still has a few hurdles to clear before being deemed ready to return.
"I think Tito made the right decision to take me out before getting worse," Carrasco sad. "It will be fine."