[3] After graduate school, Marlin worked in his first full-time coaching job as an assistant at Houston Baptist from 1983 to 1989 under Gene Iba and Tommy Jones.
[3] In the 1989–90 season, Marlin was an assistant at Marshall under Dana Altman on a team that finished second in the Southern Conference.
[3] Returning to the NCAA Division I level, Marlin was an assistant coach at Alabama from 1995 to 1998 under David Hobbs.
[9] In 10 seasons, Marlin has a cumulative 188–143 record at Louisiana (Louisiana–Lafayette before 2017), with two Sun Belt Conference regular season titles (2011 and 2018) and the 2014 Sun Belt Conference men's basketball tournament championship with an automatic qualification to the 2014 NCAA tournament.
[5] In the 2017–18 season, Louisiana reached a school record 27 wins with a first-place finish in the Sun Belt and NIT appearance.
Late in the game, Marlin and LSU coach Will Wade were confrontational towards each other, even needing to be restrained.