Dyer was introduced to football when his parents got him into the
Watford youth football system in September 1990, becoming a trainee following the conclusion of his studies in July 1991. Dyer made his
first team debut as a
substitute in Watford's 1–0 win against
Birmingham City on 17 April 1993. He signed a professional contract with the club two days later. He made one further appearance in the
First Division in the
1992–93 season, against
Oxford United. He finished as top scorer for the second successive season after scoring eight goals in 30 appearances in the
1997–98 season as the team were relegated to the First Division. He finished the season with 30 appearances and eight goals for Barnsley. After spending a week on trial at
Stoke City, he signed for the
Championship club on a one-year deal. Dyer made his debut for York in a 1–1 draw against
Mansfield Town in the
Conference League Cup third round, being substituted off in the 64th minute for Adam Boyes, in a match that was won 4–2 on a
penalty shootout after
extra time. He returned to the team in a 2–2 draw against
Crawley Town, during which he assisted Onome Sodje for the opening goal. This game was postponed and his hamstring injury forced him to miss further games. He retired from football on 23 December after being limited to three games with York because of back and hamstring injuries.{{cite news ==International career==