DERBY specialist Paul Hasleby is in doubt for Fremantle's clash with West Coast on Saturday, with coach Mark Harvey conceding the midfielder had struggled to bounce back from last weekend's gruelling loss to the Brisbane Lions.

Hasleby, a four-time Ross Glendinning Medallist, and key defender Chris Tarrant both face fitness tests ahead of the cross-town grudge match.

Tarrant jarred his knee in the 15-point loss to the Lions, and Harvey said the demands of the wet and windy conditions had taken a toll on Hasleby.

With both players in doubt, Harvey said he was considering blooding an 11th debutant in the 30th Carlton Mid Derby..

There are only six players on Fremantle's entire list yet to debut, with rookie-listed pair Hamish Shepheard and Jay van Berlo the only two that can be considered.

Ben Bucovaz, Chris Hall and Casey Sibosado are all ruled out for at least two weeks with groin injuries, while Brent Connelly is having a hip injury reassessed.

Shin stress fractures have derailed van Berlo's first season with the club, but he has played for West Perth's league side the past two weeks after a fortnight with the Falcons reserves.

He collected 21 possessions in an impressive display against Peel Thunder at the weekend.

Shepheard has been used in the ruck and as a forward for East Perth. He had 14 possessions, 12 hit-outs and two goals against Swan Districts.

Harvey said the fitness of Tarrant and Hasleby would determine the inclusion of another debutant.

"We'd like to think [Tarrant] would get up, but it's an interesting injury – I haven't come across it too many times before – so we'll test him on Friday," he said.

"He's 60-40. But that's there to be shot down because you don't really know until the next 48 hours.

"There's nothing structurally too much wrong, but sometimes it can just drag on."

With captain Matthew Pavlich likely to return and ruckman Aaron Sandilands a near-certainty after missing two matches with a minor hamstring strain, Harvey said he would have more forward options than recent weeks.

He added he wouldn't take any risks with the pair, but if Pavlich was passed fit after Wednesday's closed training session a decision would then be made on how much time the skipper spends midfield and forward.

"Both those guys coming in – provided they get through this training session – have the ability to play forward," Harvey said.

"We might find them both there at some stage.

"We've certainly got to consider how much time [Pavlich] does spend in the midfield."

The bruising clash with the Lions has also encouraged Fremantle's lighter week on the track.

However, the players have an extra day's recovery on the Eagles, who are working within the confines of six days after their loss to Port Adelaide at AAMI Stadium.