Star Fremantle midfielder Michael Barlow will miss the next two AFL games due to a broken thumb.
Barlow suffered the injury during his team's 19-point win over Hawthorn on Sunday.
Fremantle could also enter the round 22 clash with Brisbane at the Gabba without star midfielder Nat Fyfe, who is fighting his two-match ban for striking Hawthorn's Jordan Lewis.
Fremantle coach Ross Lyon has described his team's upcoming trip to the Gabba as a "frightening prospect".
The Dockers are on track to lock down fourth spot and a double finals chance after beating defending premiers Hawthorn by 19 points last week.
In contrast, Brisbane sit in 15th spot after managing just seven wins this season.
The Lions' previous appearance at the Gabba was a disaster, suffering an embarrassing 105-point loss to Adelaide.
But Brisbane has also knocked over several finals contenders this season, posting wins over North Melbourne, Gold Coast and Collingwood.
Last week's 67-point win over Collingwood at the MCG was particularly brutal, with the Lions making the most of a glut of Magpies injuries to post their best win of the year.
Lyon watched Brisbane's demolition of Collingwood on the TV, and he doesn't want his side to become another shock victim.
"It's a frightening prospect going to Brisbane," Lyon told radio 6PR. "We're building hard. We're in control of our destiny.
"But we're capable, as all teams are, of a performance that's substandard.
"It will be a fierce week, like it was last week, to get ready for Brisbane."