[6] He spent 2017 with the Columbia Fireflies, posting a 1-2 record, 2.79 ERA, and a 1.17 WHIP over 29 innings before undergoing Tommy John surgery in July, thus ending his season.

On May 27, 2021, Szapucki was promoted to the major leagues for the first time, but was optioned down to the Triple-A Syracuse Mets the next day without making an appearance.

[11] He made his MLB debut the next day, pitching in relief against the Atlanta Braves, but allowed six runs in four and two-thirds innings.

On July 13, it was announced that Szapucki would require ulnar nerve transposition surgery, ending his rookie campaign at one appearance.

[14] On August 2, 2022, Szapucki, Carson Seymour, Nick Zwack, and J. D. Davis were traded to the San Francisco Giants for Darin Ruf.

[16] On May 19, Szapucki underwent surgery for thoracic outlet syndrome, and missed the remainder of the year without appearing in a game for the Giants.