NEW YORK — Hall of Fame pitcher Tom Seaver, the star of the Miracle Mets 1969 World Series championship team, has been diagnosed with dementia at age 74.

His family made the announcement Thursday through the Hall, and said Seaver has retired from public life and will continue to work at Seaver Vineyards, which he founded with his wife, Nancy, in 1998 in California.

Seaver has limited his public appearances in recent years. He didn’t attend a dinner in January where members of the 1969 team were honored on the 50th anniversary of what still ranks among baseball’s most unexpected champs.

A three-time NL Cy Young Award winner and the 1967 NL Rookie of the Year, Seaver was 311-205 with a 2.86 ERA, 3,640 strikeouts and 61 shutouts from 1967-86. A five-time 20-game winner nicknamed Tom Terrific, Seaver was elected to the Hall in 1992 with a then-record 98.94 percent of the ballots, appearing on 425 of 430. His mark was surpassed in 2016 by Ken Griffey Jr. and this year by Mariano Rivera, the first unanimous selection.

Seaver pitched for the Mets from 1967 until 1977, when he was traded to Cincinnati after a public spat with the Mets’ chairman, M. Donald Grant.

“My biggest disappointment? Leaving the Mets the first time and the difficulties I had with the same people that led up to it,” Seaver said ahead of his Hall induction in 1992. “But even that I look back at in a positive way now. It gave me the opportunity to work in different areas of the country.”

He pitched his only no-hitter while with the Reds in June 1978 and was dealt back to New York after the 1982 season. But GM Frank Cashen blundered by leaving Seaver unprotected, and in January 1984 Seaver was claimed by the Chicago White Sox as free-agent compensation.

While with the White Sox, Seaver got his 300th win. It came at Yankee Stadium – a six-hitter in a 4-1 victory. He finished his career with Boston in 1986. He was a 12-time All-Star and led the major leagues with a 25-7 record in 1969 and with a 1.76 ERA in 1971.