Seal started his career in the
National Soccer League (NSL) in Australia where he played for
Sydney Croatia,
Marconi Fairfield and
Sydney Olympic and was the NSL top goal scorer two consecutive seasons in the
1989–90 season with Sydney Croatia scoring 15 goals, and the
1990–91 season with Marconi Fairfield scoring 19 goals. He moved to Europe in 1993, joining
Belgian side
Eendracht Aalst in Belgium. He had a trial with
Norwich City while at Eendracht but no contract was offered. In October 1994 he moved to England, joining
Bristol City for a fee of
£80,000. He moved to
Northampton Town on
loan in August 1997, scoring four times in six league games during his loan spell. Such was his form that the move was made permanent, Seal costing the Cobblers £90,000, on 12 September 1997. Seal finished his first season with Northampton as their leading goalscoring, with 14 goals in league and cup games. He was also the leading goalscorer for their reserve side with 12 goals in 10 games. He remained with Northampton until May 1999 when he was released after Northampton's relegation to
Division Three. He returned to Australia to play for
Northern Spirit in the
1999–2000 NSL season where he scored 9 goals in 20 appearances. However, after just one season Seal returned to England, where he joined
Mangotsfield United in July 2000. In the 2001–02 season, he scored 11 goals in the
FA Cup for Mangotsfield, earning him an award as the FA Cup's leading goalscorer. Seal scored 166 goals in 236 appearances for Mangotsfield, before joining local rivals
Yate Town in July 2006. Seal's stay with Yate lasted only four months, returning to Mangotsfield United in December 2006. However, his return to Mangotsfield was a short one as in March 2007, he joined
Western Football League Premier Division side
Bitton where he only made two appearances. In September 2008, Seal joined Western Football League Premier Division side
Melksham Town as part of the coaching staff and as a player. ==International career==