Fremantle skipper Nat Fyfe will be sidelined for the short term due to a mystery back injury that will require scans.
Fyfe was always in a race against time to be fit for the start of the AFL season due to a shoulder reconstruction and a subsequent infection, but it is an ongoing back injury that has kept him grounded of late.
The two-time Brownlow medallist missed last week's thrilling one-point win over Adelaide and he has also been ruled out of Sunday's home clash with St Kilda at Optus Stadium.
Dockers coach Justin Longmuir is hopeful Fyfe will be able to return soon, but there's no guarantees.
"He's had a bit of an issue with his lower back and it hasn't improved the way we want it to improve, so we'll have to do a little bit more diagnosis there," Longmuir said on Thursday.
"We're not 100 per cent sure of the cause of it. It's an injury he's had for a while and it's just flared up and hasn't settled down like we would have liked, so we'll need to do a bit more digging around ... and find out exactly what it is.
"We'll need to send him off for a scan.
"We're still hoping it's short-term. Fingers crossed he won't miss too much footy. At this stage it's a minor setback."
Longmuir said the injury had the potential to impact other parts of Fyfe's body if the Dockers weren't careful.
"Lower backs, when you get a back injury it defers pain to other areas," Longmuir said.
"You use your back for a lot of things, especially as an inside mid. So we need to make sure we get him right.
"When we get him back, we want him to stay (in the side) and we want him to be in a really good place with his footy.
"I can't give you a time frame, but he's going to miss some footy in the short term."
Fremantle will be boosted by the return of ruckman Sean Darcy from a calf injury.
