WEST Coast is not going to change its midfield set up in order to quell the influence of Hawthorn star Sam Mitchell, Eagles coach Adam Simpson says.

Mitchell has had an outstanding season and he was the difference in the Hawks' 14-point win over the Eagles in round 19 at Domain Stadium.

He gathered 36 possessions, 15 contested, and had a game-high nine clearances. But Simpson said the Eagles won’t tag Mitchell, as they haven't tagged anyone this year with the exception of Carlton's Chris Judd after quarter-time in round two.

"(Mitchell) did get away from us last time but I think (tagging) does pull you apart a little bit sometimes when you do it," Simpson said on Thursday.

"But having said that we may need to give some of their players some more attention than what we did in the last quarter-and-a-half the last time we played them."

After four years as Hawthorn’s assistant coach prior to earning the Eagles’ job, Simpson said he knows how Mitchell played.

"His greatest strength is his mind. So he'll work out ways to manipulate and expose whomever he plays on,” Simpson said.

The Eagles were beaten in contested possessions and clearances in the round 19 clash, areas they’ve usually dominated this season.

Simpson said the qualifying final would be played differently given Eagles ruck duo Nic Naitanui and Callum Sinclair were both missing in round 19.

"There will be different strategies from both sides from last time we played, because there's different personnel," Simpson said.

"Nic is a different type of ruckman as well. Every team has a plan against Nic."

The Eagles sit third in the AFL in contested possessions per game this season and third in centre clearances. Naitanui's influence has been profound.

But Simpson said the Eagles' improvement in contested ball has been the most pleasing part of the season.

"We've improved in contested possession more than our skill level," Simpson said.

"Last year we were (eighth) in the competition.

"That will be just as important as our skill level, especially if it's a wet night."

It rained heavily in Perth on Thursday and there is more rain forecast on Friday.

Simpson said his side would need to adjust if it is wet.

"We'll have to adapt to the conditions," Simpson said.

"The one thing about Hawthorn is they're pretty good in all conditions, and it's something we're striving to do as well.

"We probably haven't had the same opportunity with the wet weather, but I think we're improving in that area.”