NEW YORK -- With Jerry Koosman on the mound, it was never too late for the 1969 New York Mets.

More than five decades later, the franchise rewarded the big-game left-hander with its highest distinction.

Koosman became the fifth player or coach to have his jersey retired by the Mets on Saturday night, with his No. 36 unveiled alongside placards honoring Mike Piazza, Tom Seaver, Gil Hodges and Casey Stengel.

"Humbly thankful that they thought that much of me to retire my number," Koosman said. "I know I'm joining a great crew that's already had their numbers retired."

The 78-year-old Koosman was supposed to be honored last season, but the ceremony was postponed due to the pandemic. Instead, he was welcomed by "Kooz!" chants on a cool night in Queens ahead of Saturday's game against Washington.

His No. 36 was posted all around Citi Field, including on the pitcher's mound and the home run apple in center field. The iconic photo of him leaping into catcher Jerry Grote's arms after the final out of the 1969 World Series was superimposed over his No. 36 on the video board.

Koosman was joined by 11 family members, including his four grandchildren, as well former teammates Wayne Garrett, Ed Kranepool and Art Shamsky. Piazza, whose No. 31 was the previous number retired by the Mets in 2016, was the last to speak before Koosman's number was revealed atop the grandstands down the third-base line.

"Jerry, welcome home," Piazza said. "This is your home, and this is your family."

Koosman and his close friend Seaver both debuted with the Mets in 1967 and quickly helped turn the franchise from laughingstock to World Series champion.

The pair combined to go 11-1 with a 1.63 ERA and 11 complete games in 14 starts in September of 1969 as the Mets went 24-8 to make up a 4½-game deficit in the NL East and win the division by eight games.

Koosman gave up six runs against the Atlanta Braves in his lone National League Championship Series start before winning both World Series turns against the Baltimore Orioles. After evening the series by tossing 8 2/3 innings in Game 2, the left-hander threw a five-hitter in the Game 5 clincher to cap the miraculous worst-to-first climb for the Mets, who never lost fewer than 89 games in their first seven seasons.

"There's the old saying: Good pitching gets out good hitting," Koosman said. "So that's what happened and our pitching kind of took over."

Seaver had his number retired by the Mets in 1988, but plans to do the same for Koosman weren't announced until September of 2019. Seaver died on Aug. 31, 2020, from complications of Lewy body dementia and COVID-19.

Koosman pitched 12 seasons for the Mets, ranking second in complete games (108), third in wins (140) and strikeouts (1,799), and sixth in ERA (3.09).

He almost helped the Mets to another unlikely championship in 1973, when New York surged from last place in late August to Game 7 of the World Series against the dynastic Oakland Athletics. Koosman went 2-0 with a 3.55 ERA in three postseason starts.

"It's safe to say that in 60 years, the Mets have never had a better money pitcher than Jerry Koosman," Mets radio play-by-play man Howie Rose said while emceeing Saturday's ceremony.