OAKLAND, Calif. -- Bob Welch, pitching coach for the Diamondbacks' 2001 World Series champions and the last major leaguer to win at least 25 games in a season, died Monday night at his home in Seal Beach, Calif. He was 57.
The Oakland Athletics announced his death Tuesday.
Police said officers responded to a call for medical aid and found Welch dead in the bathroom area.
No cause of death was released. The coroner was awaiting toxicology test results, which can take eight to 12 weeks, said Lt. Jeffrey Hallock, spokesman for the Orange County Sheriff's Department.
"He was a legendary pitcher who enjoyed many of his best seasons with the Oakland A's," A's President Michael Crowley said in a statement. "He will always be a significant part of our franchise's history."
Welch was an admitted alcoholic early in his career and spent time in rehabilitation. He later co-authored a book in 1981 with George Vecsey about his addiction titled "Five O'Clock Comes Early: A Ballplayer's Battle With Alcoholism."
Welch played on five teams that reached the World Series (1978, 1981, 1988, 1989 and 1990) and won two titles, one in 1981 with the Los Angeles Dodgers and another 1989 with the A's.
Welch will be remembered most in Oakland, where he was a prominent member of the A's teams that won three straight AL championships from 1988-90, including the club that swept the San Francisco Giants in the earthquake-interrupted World Series.
Welch finished 211-146 with 3.47 ERA in 17 seasons with the Dodgers (1978-87) and Athletics (1988-94). He also was the pitching coach for the Arizona Diamondbacks when they won the 2001 World Series and has served as a special instructor for the A's in recent years. He also served as a pitching coach at Arizona State after his playing career.
"This is a sad day for the entire A's organization," general manager Billy Beane said. "Those of us who knew Bob as a teammate and a friend will miss him greatly."
Welch was drafted in the first round by the Dodgers in 1977 out of Eastern Michigan. His most memorable moment for Los Angeles might have been in the 1978 World Series, when the 21-year-old rookie struck out A's slugger Reggie Jackson to end Game 2.
"He was one of the greatest competitors to wear the Dodger uniform," Dodgers President and CEO Stan Kasten said.
Welch won the AL Cy Young Award after going 27-6 with a 2.95 ERA in 1990. His 27 wins tied him with Steve Carlton in 1972 for the most in a single season since Denny McClain's 31 victories in 1968.
Several current A's players offered their condolences on Twitter.
"Devastated to learn of Bob Welch's passing," A's left-hander Sean Doolittle wrote. "The A's organization lost not only one of its best pitchers, but one of its best people."
The A's said Welch is survived by his sons Dylan, 25, and Riley, 23, daughter Kelly, 18, and former wife, Mary Ellen.
Diamondbacks chief executive officer and president Derrick Hall released the following statement: "This is a tragic and sad day, as Bob Welch will be remembered by everyone who knew him as a great teammate and a great friend. Though he was on our Major League coaching staff for just one season, it was certainly memorable, as he guided our pitching staff to a World Championship and will always be a part of our history. Not only did he have a distinguished playing career, but as a coach at Arizona State University and then with the D-backs, he impacted many people's lives in a positive way and he will truly be missed."
