PORT CHARLOTTE, Fla. -- Everything was going so well for Shane McClanahan on Saturday at Charlotte Sports Park. His fastball lived in the high 90s, his offspeed stuff was baffling the Red Sox and he was making efficient use of his entire repertoire in his final tune-up before Opening Day.

And just like that, everything went so wrong.

Marcelo Mayer led off the top of the third inning, and it looked at first like the issue was that his foul tip had struck home-plate umpire Jeremie Rehak in the facemask.

But replays showed McClanahan dropping his left arm to his side as he released the pitch to Mayer, grimacing, turning away from the plate and hopping in place a few times before he left the field with head athletic trainer Joe Benge with what the Rays called left triceps tightness.

“Very unfortunate,” manager Kevin Cash said following the Rays’ 14-2 win. “He's gonna miss some time. We'll have a better understanding once he gets some imaging done.”

McClanahan was just days removed from making his first appearance in a game since the 2023 season. The Rays’ ace is at the tail end of his return from a second Tommy John surgery and has used the spring to show himself to be every bit the firecracker Tampa Bay fans saw debut during the '20 postseason and command two Opening Day starts (’22 and ’23) and an All-Star starting nod (’22).

“I feel for him,” said Josh Lowe, who raised his Grapefruit League average to .419 with a 1-for-2 game. “He's worked his butt off to get back into this spot, to get the Opening Day start, and for him to probably not get that start, your heart breaks for him.

“He's worked so hard to get to where he's at and to just see that happen, my heart hurts for him, but I know he'll be back and bounce back, whatever it is.”

Aug. 2, 2023, was the last time McClanahan has appeared in a regular-season big league game, and that start lasted just four innings against the Yankees before he reported tightness on the outside of his forearm that led to Tommy John surgery on Aug. 21. While the recovery period is typically 12-14 months, McClanahan did not pitch at all in ’24 as that timeline is less certain for players who have had the operation twice.

McClanahan also missed his first season at the University of South Florida while recovering from the surgery in 2016.

While the club waits to learn the severity of McClanahan’s latest injury, it remains a sobering blow for an organization that was earlier in the day happily working to break down camp and head north to begin the regular season after a relatively drama- and injury-free spring. Tampa Bay has precious little left to announce or decide roster-wise before Opening Day against the Rockies on Friday, and Cash was optimistic about both the close of Spring Training and the club’s 2025 outlook.

“There's going to be a lot of challenges throughout the course of the season -- 162 games -- a lot of things that you don't anticipate can creep up on you,” he said. “We're going to try to be as prepared to adjust as much as we possibly can.”

As the Rays now need to adjust to starting their season without their ace, one of the final roster questions was solved. Tampa Bay had six starters -- McClanahan, Drew Rasmussen, Zack Littell, Ryan Pepiot, Shane Baz and Taj Bradley -- vying for five spots. While the club had yet to make a final decision, it was understood that the sixth arm out would likely slide into a long relief role, meaning Tampa Bay would need to trim its bullpen by one man.

Though the club has made no formal announcement, each of the remaining five pitchers is still available to start Opening Day. The simplest solution seems to be to bump everyone’s turn up one day, but a somber Cash made clear that that decision was for another day.

“[McClanahan is] frustrated,” Cash said. “You feel for the person, just for what he's gone through, the rehab, the build back up and being healthy for two months of Spring Training, and then this last start. …

“Fingers crossed [that] it's a shutdown of minimal time.”