TORONTO -- Kirby Yates has been diagnosed with a flexor-pronator strain in his right arm, the Blue Jays announced Monday, leaving the club without its presumed closer to open the 2021 season.

Yates made his second appearance of the spring on Saturday and pitched a scoreless inning with two strikeouts, which kept him on track after building up with bullpens and side sessions earlier in camp. The club is still gathering information on the injury, but he is expected to miss “multiple weeks.”

The Blue Jays enjoyed a relatively healthy start to camp, but have recently lost No. 1 prospect Nate Pearson to a right groin strain, which he aggravated last week, and right-hander Thomas Hatch to “mild right elbow inflammation,” which is still being evaluated.

An All-Star in 2019, when he posted a 1.19 ERA for the Padres and saved 41 games, Yates saw his 2020 season cut short due to bone spurs in his right elbow. Upon joining the Blue Jays on a one-year-deal worth $5.5 million plus incentives in January, Yates was on track to take over the ninth inning in Toronto.

“I would say it's his job to lose,” pitching coach Pete Walker said last week, prior to Yates’ injury. “He has a tremendous track record, he's closed a lot of Major League games and he's one of the best relievers in baseball. We have a bunch of good guys down there that can close games as well, so when he's not available for some reason, someone else will be able to step up.”

That time has come.

The Blue Jays have built up their bullpen depth entering 2021, so while there’s no understating the impact of this loss on the back end of the 'pen, the club has pieces to cover Yates’ absence, regardless of how long he's out. This isn’t a new challenge, either, after manager Charlie Montoyo and his staff pieced together their bullpen without closer Ken Giles for much of the shortened 2020 season.

“It’s a big blow,” Montoyo said Monday. “We are lucky that our bullpen is deep enough that we can hang in there until Kirby comes back. I feel good about our bullpen, but it’s a big loss.”

Jordan Romano was recently described by Walker as a “closer in the making,” and the Canadian right-hander is built for the ninth inning. Romano broke out in 2020, posting a 1.23 ERA with 21 strikeouts over 14 2/3 innings before a middle finger injury cut his season short. He struck out the side on Monday against the Tigers, giving him 12 strikeouts over his five Grapefruit League innings.

Romano’s fastball averaged 96.5 mph in 2020, per Statcast, and he’s reached the 98-mph range consistently through Spring Training. His wipeout slider is a top-tier weapon when he’s spotting it, too, rounding out Romano’s classic closer profile.

The only thing working against this simple solution is that the classic closer profile has evolved. This solution won’t be as simple as replacing one arm with another in the ninth inning.

The Blue Jays also trust right-hander Rafael Dolis, who saved five games for them in 2020 and 96 over four seasons in Japan prior to returning to the Major Leagues. David Phelps gives the Blue Jays another veteran option at the back end of their bullpen, while Tyler Chatwood has impressed this spring, too. Ryan Borucki and Julian Merryweather are also expected to see some high-leverage innings.

While Romano should be considered the favorite to replace Yates’ role while Yates is injured, that could take different forms. There could be days, for example, when Montoyo decides to deploy Romano in the seventh or eighth inning when the leverage is highest, then turns to someone like Dolis in the ninth. From Romano down to the eighth or potential ninth reliever out of the 'pen, those roles will change.

“I don’t need a set inning. I kind of like it when they spring it on me like, ‘Hey, you’re going in for this inning,’” Romano said. “I like the anticipation and not really knowing. Seventh, eighth, ninth, whatever they ask me to do, I’ll be ready.”

This should also open the door a crack wider to A.J. Cole, the right-hander who spent 2020 with the Blue Jays and is back in camp as a non-roster invitee. With veteran left-hander Francisco Liriano impressing in camp as a fellow non-roster reliever, the 40-man-roster crunch will matter here, too.