AFL boss Gillon McLachlan has revealed that Saints' champion Nick Riewoldt could have been an Olympic 400 metre runner.

During a St Kilda training camp over 10 years ago, Riewoldt caught the eye of two-time Olympic gold medalist, Daley Thompson.

Thompson saw Riewoldt's incredible athletic ability and suggested he could become a 400 metre star.

"They were training at an athletics centre and were doing 400s and other things and Daley Thompson was standing there talking to (coach) Grant Thomas and asked 'who's that guy over there?' - it was Nick Riewoldt," McLachlan said on 3AW Radio on Friday morning.

"He was about 22, 23 then.

"Daley said 'give him to me, and I'll take him to the next Olympics as a 400-metre runner."

As we know, Rooey opted to continue his football career and has become one of the greatest players of our generation.

He has played over 300 games, kicked 669 goals, won six St Kilda best and fairest awards, been named in the All-Australian team on five occasions, won the Saints' goal kicking award four times and he won the 2002 AFL rising star award.