Mets in the FSL and, later, the Binghamton Rumble Ponies, batting a combined .290/.389/.416. He was named an FSL mid-season All Star and post-season All Star. He played the next two seasons in Binghamton, and was named an Eastern League mid-season All Star in both 2018 and 2019, before a brief period in 2019 playing for the Scottsdale Scorpions of the Arizona Fall League for 25 games. Mazeika was called up to the majors for the first time on August 25, 2020. He was then demoted to the alternate training site on August 26. Mazeika was called up for a second time on August 28, but was demoted a second time on August 29. On May 5, 2021, Mazeika was recalled to the majors after Brandon Nimmo was placed on the injured list. Mazeika made his MLB debut that day as a pinch hitter for Miguel Castro, grounding out to St. Louis Cardinals first baseman Paul Goldschmidt in his only at-bat. On May 7, 2021, in only his second at bat in the big leagues, Mazeika was the hero in the bottom of the 10th inning during a game against the Arizona Diamondbacks. With the bases loaded, he hit into a fielder's choice, bringing Pete Alonso at third base home. It was his first walk-off RBI, as well as his first RBI in the MLB. The Mets won the game 5–4, their biggest come-from-behind win of the season. Then on May 11, during an interleague game against the Baltimore Orioles, Mazeika, in his fourth Major League plate appearance, was the hero again. He had another walk-off fielder's choice ground ball in the bottom of the 9th inning that drove Jonathan Villar in to score, allowing the Mets to prevail 3–2. He is the first player since RBI became official in 1920 with multiple walk-off RBI within his first four career games. Although chronologically his first hit came on May 16, 2021, when he hit a solo home run against the Tampa Bay Rays, he is actually credited with a Double on April 11, 2021 during a game against the Marlins that was resumed on August 31, 2021.Patrick Mazeika 2021 Batting Game Logs On August 18, 2022, Mazeika was designated for assignment by the Mets. San Francisco Giants On August 20, 2022, Mazeika was claimed off waivers by the San Francisco Giants. He was designated for assignment on September 12. He