New York Mets A few days after the draft, and two weeks before the MCAT, the
New York Mets reached out to Hartwig and offered him a contract with a $20,000
signing bonus, the maximum allowed for an undrafted
free agent. Hartwig chose to postpone taking the MCAT and signed with the Mets. Hartwig started the 2023 season with Syracuse. In 21 appearances for the team, he registered a 4.21 ERA with 35 strikeouts and 3
saves in innings of work. The Mets promoted Hartwig to the major leagues for the first time on June 19, 2023, and he made his major league debut the same day, relieving
Max Scherzer in the ninth inning of a game against the
Houston Astros. Hartwig pitched one inning, giving up no runs on one hit and one walk. He made 28 appearances for the Mets in his rookie campaign, posting a 5–2 record and a 4.84 ERA with 30 strikeouts across innings pitched. Hartwig was optioned to Triple–A Syracuse to begin the 2024 season. On June 21, 2024, Hartwig underwent surgery to repair a
torn meniscus in his left knee and was ruled out for six–to–eight weeks. Once healthy, he made 4 appearances for the Mets, logging a 6.75 ERA with 4 strikeouts over innings pitched. On November 22, Hartwig was non–tendered by the Mets and became a free agent. On December 2, 2024, Hartwig re–signed with the Mets on a minor league contract. He made 21 appearances for Triple-A Syracuse, registering a 2-3 record and 3.42 ERA with 33 strikeouts and two saves across innings pitched. On June 27, 2025, Hartwig was released by the Mets organization.
Hanshin Tigers On July 14, 2025, Hartwig signed with the
Hanshin Tigers of
Nippon Professional Baseball. In 16 appearances for the Tigers, Hartwig logged a 2-0 record and 3.65 ERA with eight strikeouts across innings pitched.
Minnesota Twins On December 2, 2025, Hartwig signed a minor league contract with the
Minnesota Twins. ==References==