Don Cooper, a former Toronto Blue Jays pitcher who later became one of baseball’s most respected pitching coaches, died Tuesday, Sept. 22, 2026, at his home in Brentwood, Tennessee. He was 70.

His family said he died peacefully. No cause of death was released.

The Chicago White Sox, where Cooper spent 33 seasons as a coach, confirmed the news and offered condolences to his family, friends and fans. “Forever in our thoughts,” the club said.

Cooper’s major-league playing career was brief. The New York City native was drafted by the New York Yankees in 1978 and reached the majors with the Minnesota Twins in 1981.

After two seasons in Minnesota, he was traded to Toronto in December 1982. In 1983 he spent most of the year with Triple-A Syracuse, going 10-5 with a 3.21 ERA, and appeared in four games for the Blue Jays.

He allowed four runs in 5⅓ innings. He finished his playing days with the Yankees in 1985. Overall he was 1-6 with a 5.27 ERA in 44 big-league games.

His lasting impact came after he left the mound. Cooper joined the White Sox organization as a minor-league pitching coach in 1988 and became the major-league pitching coach in July 2002. He held the job through 2020 — 18 seasons under four managers.

He was pitching coach for the 2005 White Sox, who ended an 88-year World Series drought. In the American League Championship Series that year, Mark Buehrle, Jon Garland, Freddy Garcia and Jose Contreras threw four consecutive complete games, the first time a team had done so in a single postseason since the 1928 Yankees.

Chicago then swept Houston for the title. The staff posted a 2.55 ERA in an 11-1 postseason run.

Under Cooper, White Sox pitchers also threw two perfect games (Buehrle and Philip Humber) and additional no-hitters. Chris Sale, who developed into an ace in Chicago, later said he would not have been the pitcher he became without Cooper.

Ozzie Guillen, who managed the 2005 champions, called Cooper “one of a kind” and said his own career would not have been the same without him.

Former players remembered a coach who mixed old-school toughness with genuine care for pitchers and their families.

Cooper is survived by his wife, Ruby, and their three children. Funeral arrangements were pending.

For Blue Jays fans he is a small footnote from the early 1980s. Across baseball he is remembered as a coach who helped turn a rotation into champions.