Friday, 21 September 2018:

JOSH KENNEDY of the Eagles competes for the ball against Michael Hartley of the Bombers during the AFL match between the Essendon Bombers and the West Coast Eagles at Etihad Stadium in Melbourne, Australia.

Melbourne key defender Sam Frost laughs when he's asked about the last time he played on West Coast spearhead Josh Kennedy.

It was round eight of the 2014 season when a 20-year-old Frost, playing for GWS then, lined up on the Eagles forward at Subiaco in his 13th AFL appearance.

"He kicked 11 goals on me, so that's a fun one to look back on," Frost told AAP.

"But I've come a long way since then, obviously I'm in a different team and playing a different brand of footy.

"I'm a completely different player in a different head space - I'm miles away from where I was back then.

"I'm not to stressed about that ... it's a funny thing to look back on."

Frost, with four more pre-seasons and 68 games under his belt certainly won't be the lamb to the slaughter he was back then if he steps up to Kennedy in Saturday's preliminary final.

But he's more likely take the more mobile Jack Darling at Optus Stadium, leaving Kennedy to fellow key backman Oscar McDonald.

Darling was knocked out in the first quarter of their last encounter when the Demons scored a stirring win and Kennedy didn't play at all.

West Coast's twin towers carry a well-earned reputation for making life very difficult for opposition defenders into their clash, but McDonald is unfazed.

"It's a no-fear approach - you've just got to get out there and give it your best," McDonald said.

"I wouldn't say it's a daunting prospect ... there are always good players you come up against.

"We've played against Darling and Kennedy before and we know it's obviously going to be a different match to the last one with them playing.

"We think we're up to the task and it won't just be me and Frosty. We've got seven backs that play a system and will try to shut them out of the game."

AAP