Former San Diego Padres reliever Robert Stock got some bad news when he experienced shoulder soreness that led to a recommendation that he have surgery to correct thoracic outlet surgery, with the news reported by Nick Deeds of MLBTradeRumors.com via Jon Heyman of the New York Post.
Heyman also revealed that Stock is suffering from the arterial version of thoracic outlet syndrome (TOS), which means he could pitch before the end of the year. Stock has been in Mets camp as a non-roster invitee, but now he’s looking at a lengthy absence.
The 36-year old Stock has pitched in parts of five major league seasons so far in his career. He was drafted in the second round by the St. Louis Cardinals back in 2009, and he had the best stretch of his career with the San Diego Padres in 2018 when he finally made it to the majors. He posted a 2.50 ERA in 39-2/3 innings that year, but Stock has struggled since and the numbers aren’t pretty.
They include a 7.57 ERA in just 35-2/3 major league innings since then, with nearly as many walks (31) as strikeouts (39). Stock didn’t appear in the big leagues for 2022-2024, a stretch during which he bounded around between the minors, KBO and independent leagues in both the US and Mexico.
Stock resurfaced again in 2025, landing with the Boston Red Sox. He made only a pair of appearances in the big leagues, but he did pitch well at Triple-A Worcester, posting a 3.92 ERA in 85 innings as a swing man. That led to renewed interest in Stock based on his prior MLB experience.
He signed a minor league deal with the Mets this year, and he’s pitched well for the team so far this spring, with his best outing being a strong three-inning performance against the Miami Marlins as the Mets prepared for the WBC. When Stock reported some discomfort in his shoulder, an MRI revealed arterial TOS, which is the rarest from of the disorder.
The arterial form of this disorder is far less understood than the neurologically-based version, so there may be more uncertainty in Stock’s comeback. He was considered a long shot to make it to the Mets bullpen as a depth option, but Stock was also auditioning for other MLB teams, so there’s a chance that the Padres might have seen Stock again if he’d managed to stay healthy.