Adelaide coach Don Pyke has joined West Coast counterpart Adam Simpson in keeping a close guard on selections for Friday night's AFL blockbuster.
Victory for the Crows will likely earn them a home qualifying final, while the Eagles could lock in either a home elimination final or a top four finish if they win.
With the Eagles flying two possible replacements for injured star Nic Naitanui to Adelaide in an extended squad, Pyke is also keeping his cards close to his chest.
Adelaide will make at least one forced change, with key midfielder Rory Sloane suspended for a week after drawing blood when he whacked Port Adelaide midfielder Brad Ebert's head with a clumsy attempt to spoil in round 22.
Influential defender Brodie Smith is also in doubt after being concussed in Saturday's win over the Power.
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"He was pretty quiet early in the week," Pyke said on Thursday.
"We started to get him out running today. We'll wait and see what we do with that."
Wingman Paul Seedsman will miss for another week with a badly corked buttock but onballer Cam Ellis-Yolmen was "front in line" to replace Sloane, Pyke said.
With Eagles ruckman Naitanui sidelined for up to 12 months after tearing his anterior cruciate ligament, Scott Lycett will take the mantle as West Coast's first-choice big man.
What's less clear is who will support Lycett, with back-up options Jonathan Giles and Mitch Brown both flying to Adelaide after being trialled during Naitanui's absence with an achilles injury earlier in the season.
"We had a look through who they used, what roles they've used and how they've structured the team around that," Pyke said.
"For us, we plan for a different couple of alternatives but more how we're going to go about what we bring to the game."
The Crows faced their first real test in almost a month when they held off a brave Port Adelaide by 15 points in Saturday's Showdown, having come off easy wins against Fremantle, Brisbane and Essendon.
Pyke said the tight contest offered his players a reminder of what was required to play "finals-type footy" as they prepared to take on a fast-finishing West Coast.
"If you look at the numbers from the last time we played them, we were able to get the ball played in our half, which was important, and we were really strong around the contest," Pyke said.
"The fundamentals of the game don't really change. The reality is we've got to make sure we bring those consistently tomorrow night."
