James Paxton Diagnosed With Partially Torn Calf

3:10pm: Manager Alex Cora tells the Sox beat that Paxton is a “long shot” to return in 2024 (X link via MLB.com’s Ian Browne). The skipper added that Criswell, once healthy, will rejoin the rotation as the team’s fifth starter (X link via MassLive.com’s Chris Cotillo).

2:30pm: Red Sox left-hander James Paxton tells reporters that he’s been diagnosed with a partial tear of his right calf muscle (X link via WEEI’s Rob Bradford). The veteran southpaw acknowledged that it could sideline him for the remainder of the year but will still try to rehab in an effort to make it back before the season concludes.

The Sox placed Paxton on the 15-day injured list with a calf strain yesterday. The term “strain” itself, by definition, indicates there is a degree of stretching or tearing, so today’s announcement isn’t a total surprise. That said, the fact that he’s possibly facing an absence of six-plus weeks indicates that it’s a tear of some note — the latest in a long line of injuries that have plagued the talented left-hander throughout his big league career.

Paxton, 35, spent the 2022-23 seasons in Boston. He missed the entire ’22 campaign due to Tommy John surgery but returned in 2023 to pitch 96 innings of 4.50 ERA ball with more promising strikeout and walk rates. The Dodgers signed him to a one-year, $7MM deal with incentives that could take the contract up to $13MM. He unlocked all of those incentives before being designated for assignment and traded to the Red Sox in return for minor league infielder Moises Bolivar.

The Sox hoped that Paxton would help shore up an injury-depleted starting rotation, but it’s now possible they’ll receive only three starts from him. Paxton notched a solid 4.09 ERA in his 11 innings following the trade but exited his third and potentially final start after recording just two outs. He was Boston’s lone veterean acquisition prior to the trade deadline, meaning the Sox will again be left to rely on the quartet of Tanner Houck, Kutter Crawford, Brayan Bello and Nick Pivetta, with scant depth behind the group. Righty Cooper Criswell has pitched well but has little track record and is currently out with Covid-19. Fellow righty Josh Winckowski has also made a handful of starts and could see further action down the stretch.

Paxton’s injury could open the door for young Quinn Priester, whom the Sox acquired from the Pirates in exchange for infield prospect Nick Yorke. Priester, a former first-round pick and top prospect, has yet to establish himself as a consistently viable big league starter. He’s logged a 6.46 ERA in 94 2/3 big league innings to this point in his young career, but the 23-year-old has generally fared well in the upper minors — an ugly two-game stint with the Sox’ Triple-A club in Worcester notwithstanding.

It’s a tenuous situation in Boston — one that would blow up in particularly bad fashion were one of Houck, Crawford or Pivetta to go down with an injury of note. Boston traded Chris Sale to the Braves in a regrettable offseason swap that netted infielder Vaughn Grissom. He was “replaced” by right-hander Lucas Giolito, who required season-ending internal brace surgery before the 2024 campaign began. Righty Garrett Whitlock had his own internal brace operation back in May. Depth arms like Chris Murphy and Bryan Mata have also been non-factors this season due to injury.

The Red Sox currently sit in third place in the AL East despite a strong 62-55 record. They’re only two games back in the American League Wild Card hunt, landing .001 percentage points ahead of the 63-56 Mariners but trailing the 65-54 Royals for the final Wild Card spot.