WEST Coast's big man stocks have suffered another blow with ruckman Drew Petrie fracturing his hand in Sunday's 43-point win over North Melbourne.

The Eagles pulled back-up Jonathan Giles from East Perth's clash with West Perth on Sunday after the news Petrie would require surgery.

Coach Adam Simpson said it was "a tremendous effort" for Petrie to play out the game against his former club after he sustained the injury in the opening minutes.

"He got clearance to come back on, but he couldn't use it," Simpson said.

WATCH: Adam Simpson's full post-match media conference

"It's a fracture and he'll miss several weeks.

"To do what he did and to hold up his end of the bargain was so important.

"He's a very passionate man, Drew, and the type of guy you'd like to go to war with. I'm just really proud of him."

Petrie jammed his left hand in a contest and tried to stay on, but went to the bench once he realised the extent of the damage.

He was consoled by teammate Luke Shuey and spent 15 minutes in the rooms before he returned to the field with the hand strapped.

For the rest of the game, he positioned himself in rucking contests to avoid using the hand.

With No.1 ruck option Nic Naitanui to miss most of this season with a knee injury, the Eagles are down to Giles and new recruit Nathan Vardy, who competed well against Roos' duo Todd Goldstein and Braydon Preuss on Sunday.

Simpson conceded they would simply have to adapt, and backed his midfield to take up the challenge.

"We haven't got much of a choice at the moment. We've got to find a way that's going to work off perhaps not winning too many hit-outs," he said.

"We'll continue to work through that.

"We lost Nic for five to six weeks mid-year last year, so we got to work on some things then.

"We've got a bit more depth in our midfield [now] as well, and they're pretty mature bodies."

Sam Mitchell had an impressive 38-disposal debut, with the former Hawthorn midfielder influential in the Eagles' surge at the start of the second quarter.

Simpson said he had fitted seamlessly into the Eagles system, but added that the four-time premiership player could still improve.

"He's a perfectionist. In terms of since he's been at the club, he's really embraced what we've done," he said.

"Just the way he plays makes it a different dynamic. He's not [Matt] Priddis; he's a different player.

"We haven't changed our game plan because Sam's here. It complements what we're doing.

"He contributed well … there's still work to do on his game as well, even at 34 [years old]."

Despite the win, Simpson lamented how the Eagles allowed rebound off the half forward line and conceded 93 points despite the Roos' inaccuracies in front of goal.  

"We're definitely not completely satisfied," he said.

"The fact we grinded out a hard-fought win … both teams looked pretty tired towards the end but I think maybe our maturity got us over the line."