ST. PETERSBURG -- The Rays will likely be without ace Shane McClanahan for the rest of the year, as manager Kevin Cash said it is “highly unlikely” the injured left-hander will pitch again this season.

McClanahan is on the 15-day injured list due to tightness in his left forearm, which he experienced in the fourth inning of his start at Yankee Stadium last Wednesday. Cash said “probably everything's on the table” for McClanahan, including Tommy John surgery, flexor surgery and loose body removal.

“Less than ideal news,” Cash said Tuesday afternoon at Tropicana Field. “... There’s a lot of things that are, I think, available and on the table right now.”

McClanahan, who underwent Tommy John surgery in college at the University of South Florida, flew to the Tampa Bay area on Thursday and met with orthopedic team physician Dr. Koco Eaton before being placed on the injured list. He was seen Monday by Dr. Neal ElAttrache, another elbow injury specialist. 

The Rays hope to gain further clarity on McClanahan’s status after he meets with Dr. Keith Meister in Texas next Monday.

“Surgery is certainly an option, but I don’t want to get too far ahead,” Cash said. “I think in fairness to Mac and to us, he’s going to be down for a little while.”

It’s a huge loss for the Rays, as McClanahan was one of the best pitchers in baseball during the first half of the season for the second consecutive year. The two-time American League All-Star went 11-1 with a 2.53 ERA and 101 strikeouts in 96 innings over his first 17 starts before going on the injured list on July 1 due to mid-back tightness.

McClanahan was up and down in his first four starts back from the IL, as Tampa Bay dropped three of those games while he allowed 15 runs over 19 innings. He said he felt some tightness on the outside of his forearm entering the final inning of his last outing, but he was able to complete the inning before reporting the issue to Cash.

Without McClanahan, the Rays will have to lean heavily on Tyler Glasnow, Zach Eflin and Trade Deadline acquisition Aaron Civale. They figure to keep converted reliever Zack Littell in the rotation as well, and Cash said they “can kind of roll through a four-man rotation” given the number of off-days left on their schedule.

If the Rays need to fill the final spot in their rotation, they could bring back rookie right-hander Taj Bradley, mix and match with openers and bullpen days (like the one they’ll run on Wednesday against the Cardinals) or use a more traditional bulk-inning arm like rehabbing left-hander Josh Fleming or Triple-A righty Cooper Criswell.

McClanahan’s injury is just the latest significant blow to Tampa Bay's rotation. Young right-hander Shane Baz had Tommy John surgery last September and won’t pitch this season. Left-hander Jeffrey Springs (Tommy John) and righty Drew Rasmussen (right elbow surgery) went down with season-ending injuries earlier this season, and Fleming has been sidelined since June 3 with left elbow inflammation.

The Rays received better news Tuesday on Glasnow, the AL Pitcher of the Month for July who was scratched from his scheduled start Sunday in Detroit due to back spasms. The big right-hander received an injection on Tuesday morning and will be shut down for two days before potentially rejoining Tampa Bay’s rotation this weekend against Cleveland, most likely on Saturday.

“We're optimistic that he'll respond,” Cash said. “Over the next two days, let's see how he responds and then we'll look to insert him back into the rotation.”