Rays reliever Andrew Kittredge appears headed for Tommy John elbow surgery that could keep him out until 2022.The right-hander left Tuesday’s game in Boston after feeling “a little bit of pain” throwing his fifth pitch , and an MRI exam showed what the team called a sprain of the ulnar collateral ligament.That is another way of saying a tear, an injury, especially when of a high grade, that usually leads to Tommy John surgery and sidelines pitchers for more than a year.“It stinks,’' manager Kevin Cash said Wednesday during a Zoom call from Boston. “We knew we were going to have our challenges this year trying to avoid injuries like that.“Kitt provides so much for us. His consistency, I think over time he has really become a big key and a high-leverage guy for us. We’re going to miss him for the rest of the year. Then it’s up to him to talk, decide what he wants to do. I’m sure he’ll talk to (head athletic trainer Joe Benge) about what the next steps are. But it’s a big loss.’'Given that having Tommy John surgery this late in the year could force Kittredge to miss all of next season, he could opt to first try a program of rest and rehab.Kittredge, 30, has been with the Rays for parts of four seasons, posting a 4-3, 4.93 record in 93 games, including 11 turns as an opener.That’s what he was doing Tuesday, about 19½ hours after throwing the final 16 pitches of Monday’s game, earning his first major-league save. He said he “felt great” playing catch Tuesday afternoon and warming up, and normal as he started the game but then tightness and “a little bit of pain” on his fifth pitch.Kittredge was placed on the 45-day injured list, joining five other sidelined Rays pitchers. Yonny Chirinos (triceps), Oliver Drake (biceps) and Charlie Morton (shoulder) are expected back relatively soon. It’s unclear when Brendan McKay (shoulder) will return or even resume throwing. Colin Poche is out for the season after having Tommy John surgery.Chirinos seems closest to returning, with plans for him to throw a bullpen session Thursday or Friday and, if all goes well, rejoin the rotation a few days after that. Cash said they remain “very optimistic it’s gonna be a quick turnaround” for Morton, though they won’t have a timetable until he ramps up throwing.Aaron Slegers, the 6-foot-10 righty who pitched once for the Rays last year, was added to the roster, having already been with the team in Boston as a member of the taxi squad. Slegers, who was Kittredge’s spring training roommate, is built up to work as many as five innings but couldn’t get through three on Wednesday, allowing five straight hits in the eighth, including a grand slam.Despite missing several weeks of Spring 2.0 after testing positive for COVID-19, Tyler Glasnow said he felt ready physically to start the season at full throw. But through his first three starts, the issue has been throwing too many pitches, working only four innings, 4⅔ and 2⅔. Given the injuries and resulting heavy workload on the bullpen, the Rays would like him to get deep into Thursday’s game in Boston. Glasnow said he can’t think about it that way. “I kind of wear out this comment a lot, but I just have to do my business as usual,’' he said. “I never plan to have a shorter outing or a longer outing. If you prepare right, it takes care of it itself. You throw quality innings with less pitches, you throw longer. So my goal every time is just to have a good efficient outing, so I’ll prepare as normal.’'Cash said there is no straight platoon arrangement or even a set plan, but it’s clear that lefty-swinging Michael Perez, who started Wednesday against Sox righty Zack Godley, is going to get more of a share of the playing time with starting catcher Mike Zunino. Through Wednesday, Perez was hitting .176 (3-for-17) with four RBIs and a .426 OPS; Zunino .088 (3-for-34), 1 RBI, .431. “With the lack of an off-day (from last Friday until Monday), we don’t want to run either one of them into the ground,’' Cash said. “Mikey (Perez) has done a good job, he’s gotten some big hits for us. We want to keep some level of consistency for both of them.’' “It’s been a little toasty.” Slegers, on the daily morning workouts in steamy Port CharlotteThe Rays hung on to catcher Kevan Smith, who after being designated for assignment on Sunday cleared waivers and accepted an outright assignment to rejoin the Port Charlotte camp, likely sometime this weekend. …. Due to a conflict with the Lightning playoffs, Thursday’s game will be shown on Fox Sports Florida rather than Fox Sports Sun, and streamed on Fox Sports Go. ... In placing outfielder Andrew Benintendi on the injured list (strained rib cage), the Red Sox recalled right-hander Ryan Weber, the St. Petersburg native and former Ray who turned 30 on Wednesday and pitched in relief, working six solid innings. ... The Rays have won seven straight and 12 of their past 13 at Fenway, the best such run since the Blue Jays won 15 straight from Aug. 11, 1987, to Aug. 16, 1989.