Allen followed his older brother Garry (3 Senior Games in 1984) and began his senior career with South Fremantle in the West Australian Football League. Over the 1985 and 1986 seasons, Allen played 7 games in the seniors and kicked 22 Goals at an average of 3.14 goals per game. As of 2015 this was the 15th best goals per game average for the club. Allen kicked 62 goals for the Colts 1984 season and was an important part of the Bulldogs premiership victory. In Round4 of the 1985 Season for the Colts, Allen kicked 10 goals against Subiaco.