NEW YORK (AP) — Jerry Grote, the catcher who helped transform the New York Mets from a perennial loser into the 1969 World Series champion, died Sunday. He was 81.

Grote had suffered from heart issues and died in Texas Cardiac Arrhythmia Institute at St. David’s Medical Center in Austin, Texas, Mets spokesman Jay Horwitz said. Grote had been scheduled for a procedure and died of respiratory failure during the procedure, Horwitz said.

At two-time All-Star, Grote played 16 major league seasons and batted .252 with 39 homers and 404 RBIs.

“Backbone of a young Mets team who captured the heart of New York City,” Mets owner Steve Cohen and wife Alix said in a statement.

Grote had played two seasons with the Houston Colt .45s when the Mets acquired him in October 1965 for a player to be named, who turned out to be pitcher Tom Parsons.

Launched as an expansion team in 1962 to replace the departed New York Giants and Brooklyn Dodgers, the Mets finished ninth or 10th in their first seven seasons before a remarkable turnaround in 1969.

“We were not supposed to do anything,” Grote said at the 50th anniversary celebration in 2019. “And we did it all.”

Grote nurtured a young pitching staff led by Tom Seaver, Jerry Koosman and Gary Gentry, The Mets overtook the Chicago Cubs and moved into first place for the first time in their history on Sept. 10. They finished 100-62 to win the NL East by eight games, then swept three games from Atlanta in the first NL Championship Series and beat highly favored Baltimore in a five-game World Series.

“He was the glue that kept the staff together,” Mets star Cleon Jones said in a statement.

Grote was a first-time All-Star in 1968, starting for the NL in the All-Star Game at Houston’s Astrodome and batting .282.

He hit .252 with six homers and 40 RBIs in 1969, starting 100 games behind the plate. On the night the Mets moved into the division lead, he caught all 21 innings in a doubleheader sweep of Montreal.

Grote caught every inning of the postseason. He had a two-out single off Dave McNally in the ninth inning of World Series Game 2 to put runners at the corners, and Al Weis followed with an RBI single that lifted the Mets to a 2-1 win. Grote doubled off Dick Hall leading off the 10th inning of Game 4, and pinch-runner Rod Gaspar scored on J.C. Martin’s sacrifice bunt for another 2-1 victory.

“Without Jerry, we don’t win in 1969,” Mets outfielder and first baseman Art Shamsky said in a statement. “It’s as simple as that.”

Grote was the Mets’ primary catcher from 1966-71, then started sharing time with Duffy Dyer in 1972. He helped the Mets win another NL pennant in 1973. Praised for his defense, Grote made his second All-Star team in 1974.

“He was the best catcher I ever threw to,” Mets pitcher Jon Matlack said in a statement.

Following the emergence of John Stearns, Grote was traded to the Los Angeles Dodgers in August 1977, became a free agent after the 1978 season and then retired. He changed his mind three years later and split 1981 with Kansas City and the Dodgers. He had a career-best seven RBIs on June 3, 1981, hitting a grand slam off Seattle’s Ken Clay.

Gerald Wayne Grote was born in San Antonio on Oct. 6, 1942. He was a three-sport star at MacArthur High and attended Trinity University in San Antonio, where he gained catching skill with the help of former big leaguer Del Baker, an adviser to the team.

In the days before the amateur draft, Grote was signed by Houston scout Red Murff in 1962 and made his big league debut on Sept. 21, 1963. Grote entered in the fifth inning against Philadelphia at Colt Stadium and hit a sacrifice fly off Dallas Green in his first plate appearance.

Grote was traded to the Mets after Murff switched to New York and recommended his acquisition.

Twice divorced, Grote is survived by his third wife, Cheryl; son Jeff; daughters Jennifer Jackson and Sandy Deloney; and step-daughter Laurel Leudecke, according to the Mets.