Eric Cooper, who just completed his 21st year as a major league umpire after working an American League Division Series, died at the age of 52.
"This is a very sad day across Major League Baseball," commissioner Rob Manfred said Sunday in a statement.
"Eric Cooper was a highly respected umpire, a hard worker on the field and a popular member of our staff. He also served as a key voice of the MLB Umpires Association on important issues in our game. Eric was a consistent presence in the Postseason throughout his career, including in this year's Division Series between the Yankees and the Twins. He was known for his professionalism and his enthusiasm, including for our international events.
"On behalf of Major League Baseball, I extend my deepest condolences to Eric's family, friends and all of his fellow Major League Umpires. We will honor Eric's memory during the World Series. Eric will be missed by the entire Baseball family."
No cause of death was announced.
Cooper started working in the minor leagues in 1990, beginning his major league career in 1999. He was behind the plate for a trio of no-hitters -- by Hideo Nomo of the Boston Red Sox in 2001 and two by Chicago White Sox left-hander Mark Buehrle, in 2007 and 2009 (perfect game).
Cooper worked three wild-card games, 10 division series, four league championship series, the 2005 All-Star Game and the 2014 World Series.