FREMANTLE coach Mark Harvey is hoping that the decision to throw 18-year-old Zac Clarke into the No.1 ruck role against Adelaide on Saturday night will bring the best out of him.
 
In just his third game, Clarke will step into the key role vacated by injured vice-captain Aaron Sandilands with Kepler Bradley to provide support at AAMI Stadium.
 
Clarke had a quiet three-possession debut against Collingwood in round 13, but he bounced back against Carlton last week and Harvey said he saw some positive signs. 
 
"It's always difficult for the guy in his first couple of games and his first year of league football, but the kid started to evolve last week," Harvey said from Perth on Friday before flying out.

"Adelaide on the road is always an interesting challenge for a young player. Putting these guys through these circumstances early will bring the best out of them and fast-track them as quickly as we want.
 
"He's going to take the brunt of first ruck, which is always interesting, and we'll just see how he handles it.
 
"He knew yesterday he was going to be put in that position and he works closely with (midfield coach) Barry Mitchell and (ruck coach) Earl Spalding."

Harvey said Sandilands would be assessed again next week, but he is only expected to miss one week with a minor hamstring strain.

Things aren't as clear cut for Des Headland. 

"He's got a hamstring, but he might be one to two," Harvey said. 

"He's just been unfortunate and sometimes when you don't have a pre-season… you can run into soft tissue problems.

"He wouldn't normally have had these soft tissue [injuries] had he done a full pre-season."

The injuries have left Fremantle without eight of their best 22, and assistant coach Barry Mitchell said selection was becoming harder.

"The numbers are getting lower and lower each week, but I think there's probably another five or six left – that's about it," he said. 

"It is (frustrating), but that's footy – it happens to everybody.

"We haven't had a great run all year, but the last four or five weeks have been a bit difficult."

Four of Fremantle's nine debutants so far – Tim Ruffles will become the 10th on Saturday night – have been rookies.

With Matt de Boer, Greg Broughton, Clancee Pearce and Luke Pratt all debuting this season and covering Fremantle's spate of injuries, Mitchell said the AFL should consider expanding rookie lists.

"It's something the AFL probably have to have a look at, maybe you get more rookies, maybe it gets to 10 rookies so that you don't run into trouble," he said.

"We're still okay, we can still field a strong side. But the way the game is, the intensity of the game, and the attrition rate of the players, maybe it's something that needs to be looked at."

Mitchell said Fremantle would look to start strongly against the in-form Crows and he was particularly wary of their young trio Bernie Vince, Nathan van Berlo and Patrick Dangerfield.

Dean Solomon is returning after a one-match club-imposed ban, while Pratt will travel as an emergency for Fremantle.