ADAM Simpson says he hasn’t settled on West Coast's first-choice key defenders for round one, despite giving Eric Mackenzie the nod over Tom Barrass in Thursday night's win over Melbourne.

Former club champion Mackenzie played the entire match against the Demons, while young gun Barrass warmed the bench all game alongside Jack Redden.

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"Tom will play (in a practice match for East Perth) on Saturday. We had to make a decision, he played the first half of the Geraldton game (against Fremantle) so we've given Eric an opportunity," Simpson said. 

After struggling to adapt to the Eagles' zone defence in his comeback from a knee reconstruction, Mackenzie slipped behind Barrass in the pecking order in the second half of last season.

But the 28-year-old has enjoyed a strong summer and played all three JLT Community Series games to push his case for round one, finishing with an impressive 17-disposal and six-mark effort against the Demons. 

"I think he played pretty well, but that doesn't mean (he'll play round one)," Eagles coach Simpson said. 

"There's four or five spots we need to make a judgement call on after we look at the East Perth game on the weekend." 

Simpson was pleased the Eagles got through unscathed on Thursday night, while ruckmen Nathan Vardy and Drew Petrie again produced strong efforts against Melbourne star Max Gawn. 

With Jonathan Giles (thumb) overlooked for the clash and Scott Lycett (knee) also set to play for East Perth on Saturday, the Eagles' tall recruits could lead the ruck division in round one against North Melbourne.

"I thought our guys had a go (tonight). We got exposed a couple of times and a few times we handled it well," Simpson said.

"We lost the clearances by 10, but I don't think we got hurt on the scoreboard so there's going to be a balance for us on that this year. 

"(Giles) hasn't played at all. He hurt his thumb, has missed eight weeks of contact and hasn't taken a mark in eight weeks. 

"He needs to play, so he'll play on Saturday. 

"We'll just have to see (who plays in round one). It's pretty open at the moment. The boys that were playing tonight, they've got their spots at the moment."