He played in Major League Baseball as a first baseman and left fielder from 1971 to 1982 for the New York Mets, Pittsburgh Pirates and the Montreal Expos.

A native of Atlanta, Georgia, he grew up a huge Hank Aaron fan, even appropriating his idol's nickname, "the Hammer".

[4] On September 11, 1974, Milner tied a major league record by making twelve plate appearances in the Mets' 25 inning marathon with the Cardinals.

Milner was dealt from the Mets to the Pittsburgh Pirates in the first four-team blockbuster deal in Major League Baseball history on December 8, 1977.

[6][7] Milner found himself in more of a reserve role with Pittsburgh, with the 333 at-bats he logged in 1978 being his fewest outside of his injury plagued 1975 season.

His finest season with the Pirates came in 1979, when he hit 16 home runs and drove in 60 backing up Willie Stargell at first and Bill Robinson in left field.

Milner developed and refined a reputation as a reliable pinch hitter who thrived in pressure situations during his tenure with the Pirates.

Milner reached the post-season for the third time in his career as the Expos won the second half of the strike shortened 1981 season.