New York Mets team Hall of Famer and two-time All-Star Jerry Koosman died Sunday morning in Osceola, Wisconsin, the team announced. He was 83. The Mets say Koosman battled multiple illnesses before his death.

The Mets discovered Koosman while he was pitching for the United States Army and signed him to a contract in August 1964. He made his MLB debut in April 1967 and moved into the rotation full-time the next season. Koosman threw 263 ⅔ innings with a 2.08 ERA as a rookie in 1968, which earned him an All-Star Game selection and MVP votes, and a second-place finish in the Rookie of the Year voting behind Hall of Famer Johnny Bench.

In 1969, Koosman was again an All-Star, throwing 241 innings with a 2.28 ERA. He was New York's No. 2 starter in the postseason between Hall of Famers Tom Seaver and Nolan Ryan. Koosman made two starts for the Miracle Mets in the World Series, including the Game 5 clincher against the Baltimore Orioles. He allowed three runs in the complete game win and recorded all but one possible out in his two World Series starts.

From 1968-76, Koosman was simply one of the best pitchers in the game, pitching to a 2.94 ERA and averaging 223 innings per season. The Mets traded him to the Minnesota Twins for Jesse Orosco in December 1978 and Koosman finished his career with stints for the Twins (1979-81), Chicago White Sox (1981-83), and Philadelphia Phillies (1984-85).

Koosman retired following the 1985 season with a 222-209 record and a 3.36 ERA that is 39th among AL/NL pitchers with at least 3,500 career innings. He ranks 35th all-time in strikeouts (2,556), 40th all-time in starts (527), 48th all-time in innings (3,839 ⅓), and 77th all-time in pitching WAR (57.0). Koosman went to two All-Star Games and finished second to Randy Jones in the 1976 Cy Young voting.

The Mets inducted Koosman into their Hall of Fame in 1989 and retired his No. 36 in 2021. His 140 wins are the most in franchise history among left-handers and third in team history overall, behind Seaver (198) and Dwight Gooden (157). Koosman is second in Mets history in innings (behind Seaver) and third in strikeouts (behind Seaver and Gooden).

Koosman fell off the Baseball Writers Association of America's Hall of Fame ballot in 1991, his first year of eligibility.