WEST Coast coach Adam Simpson says keeping Nick Riewoldt in check will hold the key to an Eagles victory on Saturday night at Patersons Stadium.

Four-time All Australian Riewoldt is in red-hot form having taken 26 marks and kicked eight goals in his first two matches this year.

"If he plays well, they're a fair chance of winning," Simpson said.

"He's an A-grade player.”

Eric Mackenzie will likely get the job on Riewoldt, but the Eagles have to cover the loss of Shannon Hurn who is out for at least a month with a knee injury.

“We were pretty lucky last week that we had a sub who played that position in Brad Sheppard, so we don’t see why he can’t do that again," Simpson said.

"He almost played a full game and performed really well, so he’ll step into that role and we’re pretty comfortable with that.

"We’ve got a bit of flexibility in our side now, so guys can roll through high half-back, wing, deep defender.

"Those guys all play a similar position now, so we’re comfortable with Brad playing that role."

Both teams will enter the game undefeated, but have each won in vastly different style over the first two rounds.

West Coast strolled past the Western Bulldogs and Melbourne kicking 39 goals in total in two big wins.

The Saints won a low-scoring scrap with the Demons in round one before overcoming Greater Western Sydney last week in a tight arm-wrestle.

St Kilda is 15th in the league for inside-50 entries after two rounds, but Simpson is expecting a difficult challenge for his side.

"I think this week is going to be bit of scrap," Simpson said.

"I get the feeling it's going to be a fair challenge. They're going to come over to hunt and we're ready for it, but I don't think it's going to be one of those games that just opens up.

"I think it's going to be pretty tough.

"They've got some real good experience with some exciting youth as well.

"Their balance is a little bit different than the last two teams we've played. They've got a bit more experience and they seem to be up for the challenge."

Simpson was frustrated that his side lost the contested possession count after quarter-time in their 93-point win over the Demons.

Brant Colledge will come in for his AFL debut on Saturday, while Chris Masten will celebrate his 100th game and Dean Cox will equal Glen Jakovich's club games record with 276 matches.