Athletics reliever Deolis Guerra undergoes Tommy John surgery

The A’s announced that reliever Deolis Guerra underwent Tommy John surgery on Wednesday. That’ll obviously end his season and seems likely to sideline him for a decent chunk of the 2023 campaign as well.

Guerra left a late-spring appearance after feeling some forearm tightness, an ominous development that often proves a precursor to a Tommy John issue. Martín Gallegos of MLB.com reported earlier this month that Guerra would require a procedure of some kind, but it hadn’t been clear whether he’d need a full UCL reconstruction. Unfortunately, that has proved to be the case.

Coming into the year, the 32-year-old (33 this weekend) looked as if he’d take on a notable role for first-year manager Mark Kotsay. Among returning relievers, only Lou Trivino (73 2/3) worked more innings for the A’s than Guerra, who tossed 65 2/3 frames. He posted a capable 4.11 ERA, striking out an average 23% of opponents on a 12.3% swinging-strike rate. It wasn’t an overwhelming performance, but the Venezuela native showed the ability to work more than one inning and pounded the strike zone en route to decent numbers.

Guerra has appeared in the majors in each of the past six seasons (albeit just once in 2019), suiting up with the Pirates, Angels, Brewers and Phillies before landing in Oakland. He has worked 168 2/3 innings of 4.54 ERA ball altogether, compensating for a 20.4% strikeout percentage with a stingy 6.2% walk rate.

The A’s and Guerra agreed to an $815K salary over the offseason to avoid arbitration. He’ll collect that salary and service time while on the injured list, bringing him up over four years of service by the end of the season. Guerra remains controllable for another two years, but it’s possible the A’s non-tender him rather than carry him on the 40-man roster throughout next offseason.