The Cubs made Tabb a first-round pick, selected 16th overall, in the 1973 Major League Baseball Draft. He debuted in the majors in September 1976, playing in 11 games for the Cubs and batting .292.
Tabb was purchased from the Cubs by the Athletics the following February, and in 1977 Tabb got an extended chance in the major leagues. The A's were cleaning house, and Tabb was one of five players who received substantial playing time at first base for the team. Tabb batted .222 with 6 home runs and 19 RBI in 51 games. The next season, however, Oakland acquired Dave Revering from the Cincinnati Reds and installed him as their regular first baseman. Tabb managed just 9 at-bats in 1978, his last season in the majors.