LANCE Franklin has ex-club Hawthorn on notice, but it's the Hawks' flexible forwards that'll keep the Swans on high alert when they duel for the AFL's top spot.

The second-placed Swans will rely on their league-best defence to combat the reigning triple premiers at the SCG on Thursday night.

A key in who triumphs in the latest chapter of this fierce rivalry will be how well the hosts contain flying small forwards Paul Puopolo, Luke Breust and Cyril Rioli.

The Swans have conceded the fewest points against in the competition thanks to their knack for reducing scores from the turnover.

But the club’s defence coach, Henry Playfair, said the Hawks' adaptability up front presented the Swans’ defensive set-up with a specific challenge.

"With Breust, Rioli, Puopolo, they're dangerous anywhere up the ground and deep, and they mix it up a lot," Playfair said.

"(Jack) Gunston as well, who's that medium-sized or taller target they kick to a fair bit.

"The fact that they're so flexible makes them quite dangerous, and makes it hard for your defence to get set.

"So we'll have to be on our toes and ready for anything, because they keep the ball alive as well which is the other unpredictable part."

Nick Smith will spend time on Rioli, as he did when the Swans beat Hawthorn seven rounds ago.

But like many battles, he'll be a shared responsibility.

"We'll have to be open because Rioli goes in the middle and gets up high up the ground," Playfair said.

"He's really found some form and is back to his dangerous best which is really hard to handle."

The Swans are high on confidence after last weekend's away win over Geelong.

Assistant coach Stuart Dew said it was crucial to maintain momentum in the business end of the season.

"We need to consolidate it and knock off a top team," Dew said.

"They're the best team in the comp so we expect a physical game."

Jeremy Laidler won't take part after suffering a hamstring injury playing in the NEAFL last weekend.