Faced with competition for a first team place by Juan Pablo Ángel and Peter Crouch, Dublin spent several weeks on loan at First Division Millwall. In his time there, he scored two goals, against Stockport County, and Grimsby Town in five league matches to help them into the play-offs where despite Dublin's goal in the first leg of the semi final, Millwall lost to Birmingham City 2–1 on aggregate. Returning to Villa, he found himself again a first-choice striker, partnering Darius Vassell up front. Dublin was sent off at Villa Park for a headbutt on Robbie Savage in the Birmingham derby match, which ended 2–0 to Birmingham City.