NEW YORK -- The Mets’ pitching staff absorbed another blow this week, when Thomas Szapucki underwent season-ending ulnar transposition surgery on his left elbow, according to multiple sources. The Mets haven't announced the news, but team officials expect Szapucki, the organization’s 10th-ranked prospect, to be ready for Spring Training.

The procedure is not uncommon for pitchers in the years following Tommy John surgery, which can damage the sensitive ulnar nerve. Jacob deGrom underwent an ulnar transposition late in 2016, when doctors repositioned the nerve within his arm. Steven Matz did the same in '17. In both cases, the pitchers missed minimal time.

Szapucki underwent Tommy John surgery in 2017, after breaking out as a Mets prospect the previous summer. He returned to the mound in '19, but lost an entire season of Minor League development in 2020 due to the COVID-19 pandemic. This year, Szapucki struggled with his control, walking 6.2 batters per nine innings en route to a 4.96 ERA split between Triple-A Syracuse and the Majors. The left-hander earned multiple call-ups to the Mets but only appeared in one game, allowing six runs over 3 2/3 innings.

Szapucki’s surgery leaves the Mets with only one healthy pitcher among their Top 10 prospects. Third-ranked Matt Allan, the Mets’ top overall pitching prospect entering the season, recently underwent Tommy John surgery and won’t return until late 2022 at the earliest. Sixth-ranked J.T. Ginn recently recovered from Tommy John surgery himself.

The Mets did infuse their system with plenty of additional pitching talent this week, selecting college standout Kumar Rocker with their first-round Draft pick and following that up with seven more pitchers over the first 10 rounds of the Draft.

Szapucki was a fifth-round Draft pick of the Mets in 2015.