Before coaching at Mississippi State, Croom was an assistant at Alabama for 11 seasons, one as a graduate assistant coach and ten more variably as inside and outside linebackers coach. During this eleven-year period on the Alabama staff Croom participated in ten bowl games, two national championships in 1978 and 1979, and he coached four eventual NFL first-round draft picks, including Cornelius Bennett and Derrick Thomas.
He then spent 17 years in the professional ranks as running backs coach at Tampa Bay, Indianapolis, San Diego, and Green Bay. Before going to Green Bay he served as offensive coordinator for Detroit from 1997-2000, and during his tenure in San Diego was on the Chargers' staff for Super Bowl XXIX.