While also playing for Sunbury Manor and Sunbury Casuals, he progressed through the various youth ranks and eventually signed his first professional contract in 2002. He made his debut for the club in the Brentford's 1–0 victory over Plymouth Argyle in the Football League Trophy on 12 November 2002. During the match, Julian was "forced into numerous good saves.
While playing for Sunbury Manor and Sunbury Casuals, he progressed through the youth ranks and eventually signed his first professional contract with Brentford in 2002. He made his debut for the club in a Football League Trophy match against Plymouth Argyle on November 12, 2002, where he was required to make several saves.