Won the California state title in basketball in 2010 as a junior... The team was ranked third nationally and played several games on ESPNU...Also won the state title as a senior...His father, Bob, played professionally in the Phillies minor league system...He was a catcher from 1984-1987...Roomed with teammate Noah Syndergaard during the 2020-2021 offseason.
Recorded an 8.68 ERA (nine earned runs/9.1 innings) in four starts and an 11.57 ERA (six earned runs/4.2 innings) in two games in relief...Was part of the Mets' rotation for the first time since 2017...Left his final outing of the year with a fractured rib...Missed the last month and a half of the 2019 season and first two weeks of the 2020 season with separate bouts of right triceps tightness.
Appeared in 52 games and went 2-3 with a save and a 4.66 ERA (33 earned runs/63.2 innings) with 23 walks and 60 strikeouts...Posted a 1-1 record with one save and a 2.29 ERA (10 earned runs/39.1 innings) with 15 walks and 37 strikeouts in 29 games on the road...Owned the eighth lowest road ERA in the majors (min 35.0 innings)...This compared to a 1-2 record with an 8.51 ERA (23 earned runs/24.1 innings) with eight walks and 23 punch outs in 23 appearances at Citi Field...Hurled a career-high 13.0 scoreless innings from April 27-May 22 (4 H, 5 BB, 13 K)...Appeared in 50 games for the second time in his career... Appeared in a career-high 68 games in 2018...Was leading NL relievers and was fourth in the majors with 63.2 innings pitched at the time of his injury...Tossed a season-high 3.0 innings twice on April 21 at St. Louis and again on May 4 in an 18-inning loss in Milwaukee...Appeared on May 31 at Arizona and worked 1.0 scoreless inning for his first save of the year and the 14th of his career...Was his first since September 27, 2018 vs. Atlanta.
Spent the entire season in the bullpen, making 68 relief outings...Led the team with 15 holds and had the most saves (13) among players who finished the season with the Mets...Was tied for seventh among NL relievers with six wins...His 80.0 innings out of the bullpen were second-most among NL relief pitchers and eighth among all relievers in the majors...Notched 13 saves after not earning a save since his first year of professional baseball on July 28, 2011 with the rookie-level Gulf Coast Mets in his first professional outing...Earned his first major league save on May 20 vs. Arizona in a 4-1 win...Recorded the final five outs to preserve the win...Had three saves of 1.2 innings or longer (May 20 vs. Arizona, July 13 vs. Washington and July 20 at Yankees), tied for the third-most in the majors...It was the most such saves by a Mets reliever since Jeurys Familia had three in 2015...Had two 2.0-inning saves (July 13 vs. Washington and July 20 at Yankees), the most by a Mets relief pitcher since Jenrry Mejia had two in 2014...Tossed a career-high 11.2 scoreless innings from August 2-24... Also hurled 10.2 scoreless innings from May 9-25...Was the winning pitcher and scored the winning run in the 12th inning on April 20 at Atlanta...The last Met to earn a win and score the winning run in extra innings was Carlos Torres on August 27, 2015 at Philadelphia...Research courtesy of Elias...Had a 1.11 ERA (three earned runs/24.1 innings) during the day...Left-handers went 30-139 (.216) and righties were 46-165 (.279).
Made his first Opening Day roster and went 8-7 with a 5.19 ERA (69 earned runs/119.2 innings) in 25 games, 22 starts, for the Mets...His eight wins were second-most on the team behind Jacob deGrom's 15 victories...The Mets were 11-11 in his 22 starts...On the 10-Day DL from June 28-August 15, with a strained left hamstring...Over his final eight starts (August 16 to the end of the season), went 3-2 with a 3.50 ERA (17 earned runs/43.2 innings) including his first-career complete game, a rain-shortened 6.0-inning contest vs. Philadelphia on September 6...Posted a 2.25 ERA (one earned run/4.0 innings) in three relief outings...Won three straight starts while posting a 1.42 ERA from May 29-June 10...Only three other rookies in team history won three straight decisions with an ERA under 1.50...Jae Seo (2003), Jacob deGrom (2014) and Steven Matz (2016) are the others...Had a 49.3% groundball rate in 2017, which led all Mets starters (min. 10 games started)...In his two seasons in the majors, Gsellman owns a 50.4% groundball rate...Went 0-3 with a 7.07 ERA (22 earned runs/28.0 innings) in six starts from June 15-August 26...The Mets were 0-6 in those six starts.
Underwent left shoulder labrum repair surgery on October 12 at the Hospital for Special Surgery...Recalled from Las Vegas (AAA) on August 22 and went 3-2 with a 2.63 ERA (12 earned runs/41.0 innings) as a starter and 1-0 with a 0.00 ERA in one relief appearance (3.2 innings)...Tossed 3.2 scoreless innings in relief in his major league debut on August 23 at St. Louis and earned a victory after entering in the first inning...The only other pitcher in the modern era (since 1900) to earn a win in his major league debut as a relief pitcher who entered the game in the first inning was the Giants' John Montefusco on September 3, 1974...Research courtesy of Elias...Became the eighth reliever to earn a win in his first major league game in franchise history...Gabriel Ynoa also picked up a win as a reliever in his first career game on August 13, 2016...Made his first major league start on August 28 vs. Philadelphia...Went 3-1 with a 2.06 ERA (eight earned runs/35.0 innings) in six September starts...Struck out 35 and walked 11...New York was 4-2 in his six starts...His 2.06 ERA was seventh-best among major league starters who made at least five starts in September/October...Did not allow more than two runs while pitching 5.0 or more innings in each of his last four starts of the year...In innings 1-4, he had a 1.14 ERA (four earned runs/31.2 innings) and opponents batted .234 (26-111)...In innings 5-7, he had a 5.54 ERA (eight earned runs/13.0 innings) with batters hitting .308 (16-52)...Opened the season with Binghamton (AA) of the Eastern League and went 3-4 with a 2.71 ERA (20 earned runs/66.1 innings) pitched in 11 starts for the BMets before a promotion to Las Vegas...In nine starts for the 51s, he went 1-5 with a 5.73 ERA (31 earned runs/ 48.2 innings pitched).
Was named the Sterling Organizational Pitcher of the Year…For the season, he went 13-7 with a 2.89 ERA (46 earned runs in 143.1 innings) in 24 combined starts for St. Lucie (A) of the Florida State League and Binghamton (AA) of the Eastern League…Allowed 126 hits, with 37 walks and 146 strikeouts…Led the organization in wins and was third in ERA among qualified pitchers…Named to the Florida State League's mid-season All Star team…Jumped out to a 6-0 start with a 1.76 ERA after eight starts with St. Lucie (A) of the Florida State League…Was promoted to Binghamton (AA) of Eastern League where he spent the remainder of the year...Gave up 10 earned runs in 51.0 innings for St. Lucie…Went 8.0 shutout innings to turn back Palm Beach on May 4…Opponents hit .204 against him in the FSL…Was 5-2 with a 2.45 ERA (14 earned runs/51.1 innings) with two no-decisions in his final nine starts in the Eastern League.
Finished third in the South Atlantic League in ERA and first in complete games.
Was named to the New York-Penn League All Star Team...Won the Sterling Award for being named the MVP of his Cyclones club.