Brownlow medallist Nat Fyfe is in danger of missing the start of Fremantle's pre-season fixtures after suffering a serious back injury.
Fyfe ruptured a disc in his back during Fremantle's last day of training for 2015.
Scans reportedly revealed a bulging disc that was pushing against his spinal chord.
It's understood Fyfe won't require surgery, but the injury could sideline him for up to two months.
The Dockers are hopeful Fyfe will be able to resume running duties in mid-January, with his injury to be closely monitored over the next fortnight.
Fremantle kick off their pre-season campaign against Richmond in Mandurah on February 19, before facing Adelaide (February 28) and Geelong (March 12).
Fyfe's latest setback continues a frustrating run of injuries for the star midfielder.
The 24-year-old dealt with quad and groin issues during the second half of last season, before missing the final two games of the home-and-away campaign because of inflammation in his left leg.
Fyfe then fractured his left leg during the early stages of his team's preliminary final loss to Hawthorn.
Despite that injury, Fyfe played out the match and was one of his team's best players.
His status as the game's hottest player was cemented a few days later when he held off West Coast star Matt Priddis to win his first Brownlow medal.
Fyfe is a strong chance to take over from Matthew Pavlich as Fremantle skipper for 2016, with the player group set to vote on the leadership make-up in January.
Pavlich came close to retiring at the end of last season, and he's set to be rested from some games in 2016 in a bid to get him through the year.
The recruitment of star Gold Coast midfielder Harley Bennell will allow Fyfe to spend more time in attack.
Fremantle's lack of scoring potency came back to haunt them in the biggest games last season, with the team averaging just 10 goals a game during their doomed finals campaign.