Sydney Swans coach John Longmire says ruckman Shane Mumford is no certainty for Saturday night’s round eight clash with Fremantle at the SCG.

Longmire said Mumford, who was a late withdrawal from the Swans' match against Hawthorn after pulling up with groin soreness, would face a test ahead of this weekend’s encounter.

“Mummy is probably about a 50/50 for this week,” Longmire said on Monday afternoon.

“We’ll see how he pulls up probably after the session tomorrow and hopefully he pulls up OK and is able to do something on Thursday.

“We’ll give him as much time as he needs and whether that’s enough or not, it’s too early to tell.

“If he’s right to play he’ll definitely play, it’s just whether he’s had enough time this week to get right or not and we’re just not sure yet.”

The Swans will not be alone in their ruck concerns this weekend, with the Dockers also short on big men heading into Saturday night’s match.

Fremantle ruckman Jon Griffin, who has been one of the Dockers’ key players in the absence of leading ruckman Aaron Sandilands, was subbed out of his side’s 27-point win over Collingwood with a ruptured ACL, which forced Jack Hannath and defender Zac Dawson to share ruck duties.

Despite losing two key ruckmen early this season, Longmire said Fremantle proved last round that they had the depth to cover their injury losses and said the Swans would need to do the same if Mumford failed to pull up in time for Saturday night’s match.

“They have been able to compete pretty well there,” Longmire said.

“On their list they’ve actually got a number of ruckmen and it depends upon whether (Zac) Clarke comes back…and they’ve also been able to play Zac Dawson in that role as well.

“If (Mumford) doesn’t play, well then we’ll just have to come with another plan and make sure that we’re competitive in that area.”

Looking ahead to Saturday night’s match, Longmire said he expected Fremantle to be brimming with confidence following their hard-fought victory over Collingwood on Saturday night.

The coach added that the return of key players, including the talented Nathan Fyfe who returns from a two week suspension this week, will add to the strength of the Dockers’ side.

“Fremantle have been very good and have been able to cover their injuries really well and have had injuries to their key players, but will get a couple of key players back this week so they will be even better than what they were on the weekend personnel wise,” he said.

“They are a good team and they will come over here probably full of confidence.”

Following Sydney's 37-point loss to Hawthorn over the weekend, the coach added that the team had a number of key areas to work on, including the side’s ball use and movement in the forward 50.

“I didn’t think we took our opportunities with the ball,” Longmire said about the Swans performance against the Hawks.

“When we had the ball we didn’t use it very well, particularly our last kick inside 50, I didn’t think we executed that well.

“Also, our forwards probably didn’t run to smart spots and when you’re playing on (Brian) Lake and (Josh) Gibson, if you run to silly spots they’ll generally zone off you and drop off you and make smart decisions because they are such quality players.

“I think the combination of the poor ball use and the fact that we ran to not very smart spots really contributed to the lack of pressure when the ball was in opposition hands.”