McKinnon made his first grade debut for North Sydney under the coaching of former Manly-Warringah dual Grand Final winning Prop forward (1972 and 1973) and 1973 Kangaroo tourist Bill Hamilton.

He was fined $10,000 for urinating on the field during the Sea Eagles clash with the Brisbane Broncos at Lang Park in round 1, 1988.

Later in the same game he dislocated his shoulder while scoring a try and upon his return from injury, couldn't force his way back into the Bob Fulton coached side and spent the rest of the season playing Reserve Grade.

[5] Following the 1982 NSWRFL season, in which the Bears finished in a strong 3rd place, McKinnon was selected for the 1982 Kangaroo tour of Great Britain and France.

His father Harry, his uncle Donald and older brothers Doug and Max all played rugby league for the Bears.