AFL supremo Gillon McLachlan has declined to tip the winner of the grand final, instead predicting the match will be decided in his specialist position; the ruck.

West Coast and Hawthorn play off in the 2015 decider on Saturday, and McLachlan said he believed Eagles high-flier Nic Naitanui and opposing talls Ben McEvoy and David Hale were the most important men on the field.

“It’s going to be decided in the ruck,” he told ABC local radio on Friday.

“If Naitanui is going to be as dominant as he can, and all those West Coast midfielders get the ball and get out of the middle, I reckon West Coast will win.

“If Hale and McEvoy can break even with him … I think Hawthorn will win.

“Thats my view, the ruck will decide it … two blokes are going to decide a premiership, no pressure.”

McLachlan is a life member of Melbourne amateur side University Blues, where he played for a decade.