FORGET tactics, gamestyles and match-ups.

Because if West Coast doesn't stand up to Melbourne's ball hunters, the rest won't matter in Saturday's preliminary final.

"You've got to rock up and win the contest, because they thrive off that," Eagles wingman Chris Masten told AFL.com.au

"Once they get the ball going, they're so quick and damaging with the footy.

"We've got to really be pretty hard."

MEGA-PREVIEW Eagles v Demons

The numbers tell the story for West Coast. 

The Eagles have lost all six games when they have been beaten up in contested possessions by 12 or more this season.

But anything better than that, and their win-loss record is an unblemished 17-0.

In the qualifying final, West Coast trailed Collingwood in contested ball by eight at three-quarter time, and was 10 points down on the scoreboard.

But Adam Simpson's outfit got on top around the coalface (46-32) in the final term and stormed to a 16-point victory.

When Melbourne knocked West Coast over by 17 points at Optus Stadium in round 22, the Demons belted the home side (+23) around the ball.

"Our backs are elite, they're some of the best backs in the League, and so are our forwards, so … we need to really stand up in the midfield," Masten said.

"All finals footy starts at the contest.

"If we can get the ball going forward as much as them from stoppage, I think that's a huge result."

Melbourne's All Australian ruckman Max Gawn was the firestarter in round 22, with almost half his 41 hit-outs going to advantage.

Even without midfield bull Jack Viney, the Demons dominated clearances (+14), and Gawn received the maximum 10 coaches' votes after beating Scott Lycett and Nathan Vardy in the ruck and around the ground.

"I think Maxy showed what he can do against them last time, but they've learnt a lot of lessons from that," Masten said.

"We've got to play more as a team and do something, tire him out or something, because he is so dominant when he's up and about.

"But the two boys can both play themselves, so we'll back them in."

No team packs more of a punch than the Demons, who play at breakneck speed and rank No.1 for scoring (103 points per game) and inside 50s.

Apart from Sydney in round one, they are the only team to top the ton (108) against West Coast this season.

If Saturday's clash – expected to be played under sunny skies – becomes a shootout, the Eagles will rely heavily on Josh Kennedy and Jack Darling.

The star talls have combined for 80 goals despite their injury-interrupted seasons, and the Eagles hope Kennedy shook off some rust in his first game for seven weeks in the qualifying final.

"He only dropped like 25 marks or something," Masten joked.

"It was a bit slippery, but hopefully 25 (degrees) it's not going to be too slippery for him and he clunks all those.

"The boys have been giving it to him a little bit at training, and it's been all fun and games, so he'll be fired up."