 A month later, Aiden signed for Conference Premier side Hayes and Yeading on a one-month loan and immediately found himself playing games.In May 2014 O'Brien agreed a new two-year deal with Millwall with the 20-year-old being highly regarded by Millwall boss Ian Holloway and is expected to feature more prominently in his first-team plans next season.O'Brien made his first appearance of the season coming on as a substitute for Richard Chaplow against Southampton in the League Cup.