McKean, who was born in Bellshill, North Lanarkshire, was one of the favourites for the 1987 World Championships in Athletics 800 m. However, he caught the foot of Stephen Ole Marai in the final and suffered an injury which resulted in him finishing last. In first round qualifying for the 1991 World Championships in Athletics 800 m he slowed up too early before the line. He ended up third and failed to qualify. The two athletes ahead of him were eventual Gold and Bronze medalists Billy Konchellah and Mark Everett. McKean also won a silver medal in the 1986 European Championships in Athletics 800m splitting British teammates Sebastian Coe and Steve Cram, an event memorably described by Ian Wooldridge as being "like three Spitfires coming out of the sun". He set his personal best in London in 1989 at 1:43.88 min.