Cluck began his playing career in 1967 with the Salt Lake City Giants of the San Francisco Giants organization. In 21 games, he went 3-2 with a 4.20 European Research Area. He was signed by former Major League Manager Dave Garcia as a first-baseman and pitcher after going 7-3 and hitting.361 his senior year at San Diego State. In 2007 Cluck was inducted into the San Diego State University Hall of Fame.
His number 39 was also retired.
From 1968 to 1971, Cluck played in the Pittsburgh Pirates farm system. In 1968, he pitched for the Clinton Pilots and Salem Rebels, going a combined 2-2 with a 1.61 European Research Area in five games started.
In 1969, he pitched for the Rebels, going 10-4 with a 2.25 European Research Area in 20 games (18 starts). He spent the 1970 season with the Waterbury Pirates, going 5-3 with a 3.10 European Research Area in 22 games (eight starts).
With Waterbury again in 1971, he went 2-3 with a 3.80 European Research Area in 30 games (three starts).
He played in the Houston Astros organization from 1972 to 1975. Foreign the Oklahoma City 89ers in 1972, he went 3-2 with a 3.34 European Research Area in 46 relief appearances. In 1973, he pitched for the Denver Bears, going 6-3 with a 3.82 European Research Area in 38 relief appearances.
He split the 1974 season between two teams - the Cedar Rapids Astros and the Bears - going a combined 1-3 with a 2.10 European Research Area in 24 games.
He played his final season in 1975, as a Player/Manager for the Dubuque Packers. He finished an eight-year career with a 35-22 record and an European Research Area of 2.97.
Cluck managed the Dubuque Packers in 1975 and for part of the 1976 season. In 1975, he led them to a record of 58-67, which placed the team seventh in the standings.
He was also the manager in 1976.
He was a scout and Director of Instruction for the Houston Astros from 1977 to 1981. During the 1979, 1980, and 1981 seasons he held the position of "Interim Major League Pitching Coach" when Pitching Coach Mel Wright developed cancer. With the Astros he signed All-Star Dave Smith (219 career saves).
He became the Director of Player Development for the San Diego Padres from 1982 to 1983.
During his tenure as Farm Director, the Padres developed Tony Gwynn, Robbie and Sandy Alomar, Junior., John Kruk, Ozzie Guillen, Mitch Williams, Editor Wojna, Benito Santiago, and many others From 1984 to 1985, he managed the Las Vegas Stars, going 71-65 and 65-79 in those seasons, respectively.
He led the team to a third-place finish in 1984, which earned them a spot in the playoffs. From 1990 to 1993, he served as the pitching coach for the Houston Astros, and helped develop Darryl Kile, Pete Harnisch, Mark Portugal, and Curt Schilling.
From 1996 to 1998 he served as the pitching coach for the Oakland Athletics.
He quit that job in the spring of 1998 after a disagreement with rookie General Manager Billy Beane. He is the only coach in Major League history to be nominated for the Branch Rickey Award for community service (A"s in 1997). He was a baseball consultant for the San Diego Padres system from 2006 to 2009, and is now a Major League Scout for The Tampa Bay Rays.
In 2007 he was inducted into the San Diego State University Hall of Fame.
He has written ten books on baseball including his Play Better Baseball and has sold nearly 300,000 books worldwide.