ALL-AUSTRALIAN defender Jeremy McGovern's fractured thumb will sideline him from West Coast's clash with Geelong on Saturday night.

McGovern was a late withdrawal from last week's impressive defeat of Collingwood, and coach Adam Simpson said his recovery had been slow rather than him having a fresh setback.

The Eagles have also lost midfielder Jack Redden, who is nursing a tight quadriceps out of the Magpies game.

"The thumb's just giving (McGovern) a bit of grief at the moment. It hasn't got worse, it's got better, but just not to the point where he can play," Simpson said.

"We've tested it out today and we'll err on the side of caution with that one.

"I was expecting him last week, so we'll have to wait and see (if he plays against Carlton next week) but we'll give it as much time as it needs to."

Simpson confirmed key defender Harry Edwards would make his senior debut and provide more height down back in McGovern's absence but fellow backman Josh Rotham's been dropped.

Edwards had a dramatic growth spurt in the last two years, after being a midfielder throughout his career, and now stands about 200cm.

The third-placed Cats offer West Coast the chance to back up last week's stunning display against another strong opponent, and the match will be Tim Kelly's first against his old side.

ROUNDS 9-12 Check out the full fixture 

Kelly's slowish start to the season is a distant memory, and Simpson hoped the positive trajectory would continue. 

"He's a pro, albeit it's only his third season," the coach said of Kelly.

"He prepares the same every week and the output we've got from him has been pretty good this season – it's got better every week.

"We're not putting too much pressure on him. We just want him to get out there and play his role and hopefully we can complement him with the rest of our midfielders.

"Obviously, it's a different type of game when you're playing your old side but it's not the first time it's happened and it won't be the last."

Simpson said it was unrealistic to expect a repeat of the Collingwood performance but that his team had found the "identity" of its playing style.

"It's not built around kicking 16 goals, although we'll take it," he said.

"We think we're defending better, putting a bit more pressure on in the game, our midfielders have clicked a bit and at the weekend we were really efficient in the front half.

"We wouldn't have thought that type of output would happen every week, but the pillars and the platform of which we built that, we're hoping that's consistent – and it needs to be, to beat the Cats."