FREMANTLE coach Mark Harvey has suggested that sensitive team information was leaked from his camp in the build up to the last Western Derby, stoking the rivalry between the two WA clubs ahead of Sunday's high stakes clash.

West Coast won the last derby in round eight this season by 33 points, despite the dramatic pre-match withdrawal of key midfielders Daniel Kerr and Andrew Embley, who were replaced by Andrew Gaff and Brad Sheppard.

Harvey, who took issue with those withdrawals at the time, said his concerns did not relate to late team changes, but "personnel structure".
 
He joked at Thursday's joint press conference with West Coast coach John Worsfold that the AFL might have its own phone-hacking scandal emerging, but his concerns about team intelligence being leaked were serious.   
 
"A lot of things happened throughout the course of the week and then in the lead-up to that game," Harvey said from Patersons Stadium. "I think some of our intelligence got out.

"The interesting part about these games is that you've got your own game plan and whether that holds up, and sometimes you rely on match-ups and sometimes you rely on your planning and strategy of pulling the opposition game plan apart.

"So we'll see in time. But I'd like to think our team is in a better position than it was last time."

Asked whether he believed the information was leaked from within his own camp, Harvey said he had a "fair idea" but wouldn't speculate, later adding that, "verbally, what you say, you can't shut that up sometimes".
 
He suggested asking Worsfold how the information got out, with the Eagles coach replying, "I'm not sure where all that's come from."

The big selection issue at Fremantle this week is whether ruckman Aaron Sandilands will return from a toe injury, having missed six of the last seven games.

Harvey said the star big man would be monitored at Thursday's closed training session, with the likelihood he will be named in the 25-man squad and then assessed closer to Sunday's match.

"When you're faced with being four days out like we are now, a lot can happen," the coach said.

"We're not medics; we assume, we think and we hope, but the reality is that time tells you in the end whether the player is going to play.

"Part of the season now, this run home, is about managing your players and your list and seeing whether your players are tired or not, the ones that have played all year.

"Now the last time we played West Coast, there'll be 10 players that didn't play in that game."

Ruck recruit Jon Griffin has played every game Sandilands has missed this season, while young ruckman Zac Clarke has played the last six games in a variety of midfield roles.

Harvey said he would consider running Clarke with West Coast sensation Nic Naitanui, mirroring the Eagles' occasional tactic of using two ruckmen in centre square stoppages.

"We've had Zac in there as well at the same time as Griffin," he said. "Not a lot, but spasmodically. We understand that that's a real strength of West Coast so it's how we combat that … it might be intriguing."

Nathan Schmook covers Fremantle and West Coast news for afl.com.au. Follow him on Twitter: @AFL_NSchmook