Fremantle small forward Sam Switkowski was unable to see out the Dockers' season opener against Geelong on Saturday due to a groin injury.
Switkowski came from the GMHBA Stadium field in the third term after grimacing in the wake of the contest in Fremantle's forward 50, holding his thigh as a result.
The crafty Dockers attacker underwent assessment on the interchange before the Dockers decided to pull the trigger on their tactical sub change, with Switkowski replaced by Heath Chapman midway through the third quarter.
A groin injury is likely to force Switkowski to the sidelines for at least one match, placing his prospects for next week's clash against Sydney in some doubt.
The Dockers have following matches against West Coast, the Western Bulldogs and Richmond, the latter coming in Gather Round.
Switkowski endured an interrupted final month of his pre-season, with concussion from the Indigenous All Stars game seeing him sidelined under the AFL's protocols.
He was still able to suit up in Fremantle's second game of the pre-season against the Demons earlier this month.
The Dockers are without star recruit and fellow small forward Shai Bolton, who is dealing with a lower leg concern of his own, however the ex-Tiger is expected to be ready for Round 2 when Fremantle host the Swans.
Nat Fyfe (knee), Michael Walters (knee), Hayden Young (hamstring) and Sean Darcy (ankle) are also sidelined through injury for the start of the season.
