[1] Warren spent two years in development,[1][2] playing in the VFL, for Tasmania in 2007 and Werribee in 2008, before making his senior AFL debut for North Melbourne in Round 4, 2009.

[1] Warren impressed coaching staff of the club with his performances, especially his four-goal haul against Brisbane at Etihad Stadium in Round 10.

Warren played five consecutive games after his debut, but broke his leg in Round 13[3] and missed the rest of the season.

[2] Despite his broken leg, Warren was re-signed by North Melbourne in August 2009, with list manager, Cameron Joyce, stating that "It was a priority for us to lock Ben in", due to interest being shown in the Queensland native from the new Gold Coast team.

[5] He continued playing with Werribee after being delisted, and he was the leading goalkicker in the completed 2013 VFL season including finals with 59 goals (he finished third in the league's goalkicking award, the Frosty Miller Medal which is based on home-and-away goals only).