Born in Snohomish, Washington, Averill broke into the major leagues in 1929 (at the age of 27) with the Cleveland Indians. He played for Cleveland for over ten years, and remains the all-time Indian leader in total bases, runs batted in, runs, and triples. He also remains 3rd in all-time Indian hits and doubles, and 4th in all-time Indian home runs and walks. During his time in Cleveland, the team never finished higher than 3rd.
Averill was traded to the Detroit Tigers in the middle of the 1939 season (June 14). The following season his playing time was limited, but the Tigers reached the World Series. In the seven-game series against the Cincinnati Reds, the 38 year old Averill went 0-for-3 in three pinch-hit attempts. The Reds won the series 4 games to three.