He umpired two Test matches in the 1993/94 season. Shane Warne took 12 wickets in the match. Sheahan umpired 5 One Day International (ODI) matches between 1993 and 1994.
Altogether, he umpired 34 first-class matches in his career between 1989 and 1999.
His first match was between Australia and New Zealand at Bellerive Oval, Hobart on 26 November to 29 November 1993, won by Australia by an innings and 222 runs, with Michael Slater, David Boon and Mark Waugh scoring centuries, and Shane Warne and Tim May taking 9 and 7 wickets respectively. Sheahan"s other Test match was between Australia and South Africa at Sydney on 2 January to 6 January 1994, won by the visitors by 5 runs when Australia failed to reach a target of 117 runs.
