 Playing mainly as a centreman, Whinnen established himself in West Perth's league team, winning the Breckler Medal in 1962 and 1964 as the club's best and fairest.He also finished second in the Sandover Medal in 1964, polling 22 votes to finish one vote behind Barry Cable, the winner.Whinnen made his state debut for Western Australia against the Victorian Football Association (VFA) in 1963.