The Red Sox announced this morning that the club has recalled right-hander Naoyuki Uwasawa, whose first appearance with Boston will be his big league debut. Left-hander Joely Rodriguez was designated for assignment to make room for Uwasawa on the club’s active roster.
Uwasawa, 30, signed a minor league split contract with the Rays back in January but was traded to the Red Sox after he activated an assignment clause in his deal that obligated Tampa to deal him to any club willing to offer him a 40-man roster spot. Boston indeed added Uwasawa to their 40-man, though he began the season at Triple-A after not making the club’s Opening Day roster. Since then, the right-hander has made three starts with Worcester with a 4.80 ERA in 15 innings. While those early results have left something to be desired, Uwasawa’s 26.1% strikeout rate in the minors so far is reassuring after the righty punched out a meager 17.8% of batters faced in Japan last year.
While Uwasawa did not strike out many batters during his time in Nippon Professional Baseball, it’s impossible to deny that the right-hander was effective. Across nine seasons with the Hokkaido Nippon-Ham Fighters, Uwasawa posted a strong 3.19 ERA in 1,118 1/3 innings of work. While he struck out less than 20% of batters faced during his time in Japan, Uwasawa posted an ERA below 3.50 in each of the past six seasons. That includes excellent results in 2023, when he posted a 2.96 ERA in 170 innings despite the aforementioned low strikeout rate.
It’s not yet clear what role Uwasawa will occupy with the Red Sox now that he’s been promoted to the big league club. Injuries to Brayan Bello, Garrett Whitlock, and Nick Pivetta have left depth options Josh Winckowski, Cooper Criswell, and Chase Anderson to step into the club’s rotation alongside Tanner Houck and Kutter Crawford. It’s feasible to imagine Uwasawa taking a rotation job and pushing either Anderson or Winckowski back to the bullpen, though its also possible that Uwasawa himself has been called up to be a multi-inning relief option for the club. [UPDATE: Uwasawa will indeed be used as a long reliever, manager Alex Cora told The Athletic’s Jen McCaffrey and other reporters.]
Making room for Uwasawa on the club’s roster is Rodriguez, who has struggled to a 6.55 ERA in 11 innings of work this season with a 5.25 FIP. It’s a very similar line to the one the lefty posted with Boston last year, when he posted an identical 6.55 ERA in 11 frames with a 4.71 FIP. He was limited to just those 11 innings last year by oblique, shoulder, and hip injuries that cost him the majority of the 2023 season, though his repeat performance after re-signing with the club on a minor league deal this past winter seems to have been enough for the Red Sox to decide to move on from the 32-year-old southpaw.
Boston will have seven days to trade Rodriguez or pass attempt to pass him through waivers. Should he make it through waivers unclaimed, the Red Sox will have the opportunity to outright Rodriguez to the minor leagues, at which point Rodriguez would be able to choose between remaining with the organization as non-roster depth or returning to the free agent market in search of greener pastures elsewhere. Even without Rodriguez, the Red Sox bullpen figures to be well-stocked with lefty relief options. Brennan Bernardino and Cam Booser are the two southpaws currently in the club’s bullpen, with non-roster veteran Lucas Luetge and youngster Jorge Benitez among the club’s depth options from the left side.