Forsyth began his senior career at UCD. In 2007, he represented the Irish under 19s team in the Oporto Tournament in Portugal, where he received two caps against Portugal and Ukraine. He also played for the UCD under 18s team, they reached the semi final with Forsyth scoring several goals along the way. He also represented the Irish universities team. Forsyth was a leading figure for UCD's under-21 squad during the 2007 season before he broke into UCD's first team during the second half of that season. A solid 2007 season was capped off for Forsyth when he helped his UCD team to win the Under 21 League of Ireland with victory over St. Patrick's Athletic after a tense penalty shootout on 15 November 2007 in the final match held at Belfield Park.