He appeared in eight seasons in the major leagues with the Boston Red Sox (1960–65), Chicago Cubs (1966) and Houston Astros (1967).

Signed by the Red Sox as an amateur free agent in 1952, he did not make his major league debut until 1960 at age 27.

As a starting pitcher, he threw one complete game: on July 15, 1964, he defeated the contending Chicago White Sox, 11–2, at Fenway Park, allowing only four hits.

[1] In 3811⁄3 career innings pitched, Earley surrendered 400 hits and 188 bases on balls.

His best season was 1964 when he played in 25 games for the Red Sox and had an earned run average of 2.68 and an Adjusted ERA+ of 143.