Hayden Young will miss up to three matches with an ankle injury in another blow to Fremantle's fading AFL finals hopes.
The Dockers (7-9) have lost four of their past five matches and are at long odds to upset flag favourites Collingwood at the MCG on Saturday.
Influential midfielder Caleb Serong will miss that clash through suspension and has now been joined on the sidelines by Young.
The skilful defender was sent for scans after experiencing ankle soreness following Fremantle's horror 53-point home loss to Carlton at the weekend.
In a statement on Wednesday, the Dockers said they expect Young to miss "between one to three weeks".
"It's a low-grade ankle injury," Dockers high-performance manager Phil Merriman said.
"We need to make sure Hayden hits his markers over the next week or two.
"It's an open-ended return to play as we will be guided by how his ankle reacts from day to day."
Young was limited to just five games in 2020 - his debut season - because of a serious ankle injury, while hamstring issues kept him to eight matches the following season.
The 22-year-old has played 38 of a possible 40 games over the last two seasons.
