He played for the 1973 and 1974 World Series champion Oakland Athletics, though he was never on a postseason roster.

Hosley was removed from the A's major league roster and selected by the Chicago Cubs in the Rule 5 Draft on December 2, 1974.

[2] This led to Hosley's best showing in the majors in 1975, when he batted .255 with 6 home runs in 62 games while splitting time behind the plate with Steve Swisher and George Mitterwald.

Despite these hitting numbers, which were good for a catcher at the time, he was placed on waivers by the Cubs just a few games into the 1976 season, and he was claimed by Oakland.

He remained in the A's farm system until 1981, when he was released on August 27 after one final stint at the major league level, during which he went just 2-for-21.