Heaney started out playing on his native Teesside before being signed by London club Arsenal on schoolboy forms in January 1987. He was part of the side that won the FA Youth Cup in 1987–88 and turned professional in 1989. After spells on loan at Hartlepool United and Cambridge United, he made his Arsenal début as a substitute against Sheffield United on 18 April 1992. A winger with considerable pace, he was on the fringes of the Arsenal first team over the next two seasons, before being suddenly sold by George Graham to Southampton for £300,000 in March 1994. He made nine senior appearances for Arsenal in total, failing to score. He became Alan Ball's third signing for the Saints and scored his first goal against Newcastle United on 22 March 1995. Saints had failed to win a game since before Christmas and had dropped into 20th place, just above the relegation zone. Heaney came on as a substitute with Saints 1–0 down, and with four minutes left he prodded home a loose ball after a save by Pavel Srníček from Gordon Watson's header. Watson and Neil Shipperley completed the scoring to see Saints run out unlikely 3–1 winners. Saints then managed to climb up the table to finish in 10th place. According to Holley & Chalk, Heaney "had the ability and pace to turn matches, but could frustrate with a tendency to run up blind alleys." Heaney made 61 league appearances for Southampton in two and a half seasons, before being sold for £500,000 to Frank Clark's Manchester City in November 1996. Heaney had a loan spell with Charlton Athletic in 1997–98. He was part of the Valiants side that played against Sunderland in the dramatic 1998 Championship play-off final which they won 7–6 on penalties after a 4–4 draw to earn promotion to the Premier League. Heaney though only started sixteen matches during his two-and-a-half years with City. He eventually left Maine Road in August 1999, to link up at the Ashton Gate Stadium with Bristol City. Heaney then linked up on a free transfer to Darlingtonin the summer of 1999 for £30,000. He became a crowd favourite as helped take the club to the 2000 Third Division play-off final. Playing as a left winger he scored five goals for the club altogether. Heaney then joined up with Scottish side Dundee United for £175,000 in July 2000. Being described by club chairman Jim McLean as a "bad" signing, Heaney went on to make only fourteen appearances for Dundee. On the 4 December, 2001 he moved on to Plymouth Argyle. Heaney eventually retired a year later due to injury.
After football
After retiring, Heaney left football and became CEO of Judicare, an English firm of Solicitors that deals with international legal issues and is known particularly for recovering monies invested into problematic property abroad, based partly on his own problems investing in Spanish property.
