Cassar began his career as eighth round draft pick for the Dallas Burn in 1996 before moving to new franchise team the Miami Fusion in March 1998. Cassar was one of the players left high and dry when Miami Fusion folded in the close season of 2000-2001, but he was drafted by Dallas Burn in the supplemental draft in January. He was taken by Bolton Wanderers as a back up to its more established keepers in March 2002 in a deal which would last until the end of the 2001-2002 season. He did not make the team and Bolton did not offer him a long term contract. He had a trial at Ipswich in the summer and came close to a permenant deal.