He played in Major League Baseball for the St. Louis Cardinals, Houston Astros, Chicago Cubs, Detroit Tigers, and California Angels.

[1] As a minor leaguer with the Tulsa Oilers in 1972, Kelleher set an American Association record for shortstops with a .979 fielding percentage.

[5] He spent most of the season in the minors with the Denver Bears, but had two stints with the big league club that year.

[8] His most notable moment as an active major-league player happened in the second inning of a 9–4 Cubs win over the San Diego Padres in the second game of a doubleheader at Wrigley Field on August 7, 1977.

The 5–9, 170-pound Kelleher fought 6–6, 210-pound Dave Kingman who had successfully broken up a double-play attempt with a hard slide after being hit by a Steve Renko pitch.

[16] He was hired to serve as first base coach and infield coordinator for the major league team before the 2009 season.

[17] Kelleher worked extensively with Eduardo Nunez to improve his throws to first base and cut down on errors.