In 2002, Joe was loaned out by the London Broncos to the Huddersfield Giants to gain experience in their Senior Academy side.

He started the 2003 season with a similar loan-out at Leeds Rhinos before being recalled to the London Broncos to make his Super League début.

[citation needed] Mbu joined the National League One team Doncaster for the 2007 season and was appointed captain.

He rejoined the renamed Harlequins RL midway through the 2007 season due to Doncaster's financial difficulties.

[citation needed] In October 2010 London Skolars appointed Joe Mbu as their head coach.