Hawthorn coach Alastair Clarkson says his side's key defenders can't match Sydney for size and weight and could struggle if the Swans midfield gets on top in Saturday's AFL grand final.

Adelaide tall forwards Kurt Tippett and Taylor Walker kicked four goals each in the Crows' narrow preliminary final loss to the Hawks on Saturday.

Tippett was particularly dominant, taking 11 marks against Ryan Schoenmakers, who conceded six goals to Collingwood's Travis Cloke in Hawthorn's previous final.

Clarkson said the Swans' attack had the ability to do something similar against Schoenmakers and Josh Gibson if their midfield was given the freedom that Adelaide's was at times in the preliminary final.

"Both Josh and Schoey are undersized defenders, they're 90kg at best," Clarkson said on the Nine Network's AFL Footy Show on Thursday night.

"If the ball goes in there quickly like it did against Adelaide and they're playing against blokes that are 6-8cm taller than them and 10kg heavier they're going to be in a bit of strife.

"That will be the same against the Swannies, we're undersized against the Swans' forward line as well.

"If we allow the Swans to move the ball into their forward line like at different stages we allowed the Crows to, then our defenders are going to be in a bit of strife.

"So we've put enormous onus on the midfield and the forward line to put some pressure on."

But Clarkson expected a more congested, low-scoring fight with the Swans than the free-wheeling style of their preliminary final against Adelaide.

"We don't think it's going to be like that on Saturday," he said.

"It's going to be a fierce old contest against the Swannies.

"Sometimes games of footy pan out like that, but not grand finals usually, so we'd expect a pretty torrid affair."