On 3 January 2008, after failing to establish himself in Blackpool's Championship side, Forbes signed an 18-month contract with Football League One club Millwall despite recently being managed by Kenny Jackett who released him at Swansea City over a year earlier. Forbes however only played 13 times for the club and struggled to establish himself as a first team player. Forbes signed for Grimsby Town, managed by Mike Newell, on 2 February 2009, signing on loan until the end of the 2008-2009 season. In his second game he scored an overhead kick to equalise in the 3-3 draw with Barnet.
Forbes
Mike Newell