Hawthorn's AFL dominance over Collingwood could be derailed with the loss of star forward Jarryd Roughead, who is recovering from surgery to remove a skin cancer.
While the Hawks regained Cyril Rioli for the big Friday night clash at the MCG, they will be without Roughead and key defender James Frawley (shoulder).
Roughead is out for at least two to three weeks and the Hawks are confident Frawley can return in about a month.
Earlier this week, Magpies coach Nathan Buckley praised Roughead, a three-time premiership forward and one of the Hawks' most-important players.
Buckley rates him "the most dominant big man in the competition over the last five or six years".
Roughead starred again last Saturday at the MCG with 29 disposals and a goal in the win over Essendon.
The Hawks have brought in Matt Spangher and Ryan Schoenmakers to replace Roughead and Frawley.
Billy Hartung will replace Rioli, who missed last weekend for a funeral in Darwin.
Hawthorn boast a seven-game winning streak over Collingwood and the stakes will be high on Friday night.
The two teams are on eight wins and the victor will take outright fourth position on the ladder.
Collingwood have also made big changes, bringing in high-profile father-son recruit Darcy Moore and Brayden Maynard for their senior debuts.
They will replace Paul Seedsman, who has been dropped, and Tyson Goldsack (knee).
While Roughead and Frawley are big losses, Clarkson says it means they can experiment with how they lined up.
"I dare say we're going to have to bring in some height, but it will give us the opportunity to change our mix in both our front end and back end in terms of the height of players there," he said on Thursday morning.
The average margin in their past seven wins has been 42 points, but Clarkson feels the Magpies have improved.
He is impressed by their four-game winning streak, as well as the close loss to competition front-runners Fremantle.
"They're really tenacious and they've bought a lot of different players into their side over the past 12 to 18 months and they've started to gel together well," Clarkson said.
"We've noticed things they're doing that's made them a better side and that's producing better results for them and we're expecting a fierce contest."
