Fremantle expect unlucky key position player Alex Pearce to miss up to two months of the AFL season because of a knee injury.
An ankle injury will sideline fellow tall defender Joel Hamling for at least a month.
The unlucky pair missed the entire 2020 campaign because of injuries and were cut down again during Saturday's round-one defeat to Melbourne.
The Dockers on Monday confirmed Pearce will likely miss six to eight weeks, while Hamling will miss four to six weeks.
"Unfortunately, Alex sustained a medial ligament injury," Fremantle football manager Peter Bell said.
"He's had a really unlucky run for a long period of time now.
"Alex will be in a knee brace for four weeks, at which point we'll reassess after the brace comes off.
"(For Hamling) it's his left ankle ... the deltoid ligament on the inside of the ankle," Bell said.
"It's a little bit more complicated because Joel's also pulled a small piece of bone away from the ankle as well.
"He'll be in a moon boot for a couple of weeks and then we'll reassess from there."
Young speedster Michael Frederick (calf) may be available for the Dockers' round-two clash with Greater Western Sydney.
However, star forward Michael Walters (hamstring) will miss at least one more week.
"He's progressing well, we'll just reassess how he's going through main training this week," Bell said.
"At the moment everything is going really well with his hamstring reconditioning."
