Weissert started the 2019 season with the Tarpons and was promoted to the Double-ATrenton Thunder, where we posted a 1.88 ERA over 14 relief appearances and was eventually promoted to the Triple-AScranton/Wilkes-Barre RailRiders for the team's postseason.[1]Baseball America rated Weissert as having the best slider in the Yankees' minor league system going into the 2021 season.[6] After starting the year with the Yankees' new Double-A affiliate, the Somerset Patriots, Weissert was promoted to Scranton/Wilkes-Barre after posting a 0.71 ERA in 12+2⁄3 innings pitched over 12 appearances.[7] In 2022, Weissert served as Scranton/Wilkes-Barre's closer.[8]
On August 25, 2022, the Yankees promoted Weissert to the major leagues.[9] In his major-league debut that night, he hit a batter with his first pitch, committed a balk, hit another batter with his second pitch, and allowed two walks before being removed from the game.[10] On August 30, he collected his first career win after tossing two scoreless innings in a 7–4 victory over the Los Angeles Angels.[11]
The Yankees optioned Weissert to Scranton/Wilkes-Barre to begin the 2023 season.[12]