Fremantle ruckman Liam Reidy could be expected to receive a call-up to debut for the Dockers await as the club awaits the results of Sean Darcy's ankle injury that has already ruled him out for this weekend's match.

Fremantle for most of the year have run with a two-ruck combination of Luke Jackson and Darcym but with the injury Reidy may have to step into the role to continue Fremantle's strategy.

Fremantle coach Justin Longmuir spoke with reporters on Wednesday explaining how Reidy has been performing in the WAFL over the last month, bringing him into contention to debut and the decision he will have to make in order to still get the best out of Jackson.

"Whether we go with another ruck or a key forward or we go smaller, they're the three options," Longmuir stated

"We've got to make sure the players who come in are in good form and able to contribute in the right way. He (Reidy) has been building. He probably started the year a little bit slow, he's had a few hiccups along the way, but he's had some consistency over the last three or four weeks.

"Clearly Luke is our second-best ruck on the list, so we've just got to weigh up whether he's best served in the ruck or forward."

In Rounds 13 and 14 Darcy had been ruled out during those games due to a hamstring injury that forced the Dockers to attempt a new strategy with Jackson being the main ruck and Josh Treacy as the secondary, resulting in losses in both games that has now sparked the new idea of bringing Reidy in to keep Treacy forward.

But concerns rose from those two games with hip soreness complaints from Jackson after taking the bulk of the ruck contests. However, Longmuir has suggested that Jackson will have become accustomed to the role and that it won't be an issue this time.

"It is [a consideration]. Some of the concerns were caused off the back of his spike in ruck loads. He went from second ruck and minimal ruck playing mostly forward to all of ruck," Longmuir said.

"That was a big jump, which he wasn't used to. This time hopefully he's used to it, because he's already been through it and he's had that taste for being a No.1 ruck and his body is up to it.

"We think he should be right."

Fremantle play the Sydney Swans at Optus Stadium on Saturday at 5:40 pm local time