He spent four full seasons in the Western Hockey League with three different teams. His top junior season was his third, with the Spokane Chiefs, when he scored 31 goals and 101 points. The trade to his third junior team, the Medicine Hat Tigers, was his most rewarding, as a result of a Memorial Cup championship at season's end. The Montreal Canadiens selected Dundas in the 1985 Entry Draft, and he soon found himself playing in their system with the American Hockey League's Sherbrooke Canadiens.
Unable to crack the Canadiens roster during his tenure, Dundas left the organization and signed with the Toronto Maple Leafs as a free agent on October 4, 1989. Though most of his season was spent with their NHL affiliate in Newmarket, Dundas did get to play at the NHL level with Toronto, suiting up for games during the 1989-90 season. Dundas did record one point, but registered 25 penalty minutes.
Dundas left professional hockey after the '89-'90 season to become a full-time pastor.
Rocky is now currently working for Trimark Sportswear Group with Derek Milne.
Dundas worked as a youth pastor at Bayview Glen Church. Dundas went on to become the co-lead pastor at Summit Community Church in Richmond Hill, Ontario.