Gumbleton was withdrawn from WAFL duties over the weekend due to a leg injury.
He has a history of soft tissue injuries and has been sent off for scans to determine the exact nature of his latest problem.
The 26-year-old has endured a tough time since making the switch from Essendon to Fremantle at the end of last season on a one-year deal.
Gumbleton managed only 35 matches in seven seasons with the Bombers and missed the first three months of this year after tearing his hamstring in February.
His latest setback could ruin his chances of earning another one-year deal at the Dockers.
In better news for the Dockers, forward Michael Walters could return to action in the WAFL as early as this week.
Walters, who booted 46 goals last season, has been grounded since dislocating a tendon in his left ankle against Hawthorn in round three.
It was initially feared he would miss the rest of the season, but the 23-year-old is back in full training and a chance to line up for WAFL side Peel Thunder in Saturday's clash with South Fremantle.
Dockers skipper Matthew Pavlich remains in doubt to take on Geelong at Simonds Stadium on Saturday night after he was concussed in last week's five-point win over Carlton.
His vision became blurred after copping an accidental elbow to the face, and he'll have to pass a series of concussion tests this week if he is to take his place in the team.
Utility Tendai Mzungu is almost certain to miss the match after injuring his hamstring.
Former Demon Colin Sylvia and wingman Anthony Morabito pressed their claims for a recall after producing strong performances in the WAFL.
Morabito tallied 31 possessions in Peel's win over Perth, while Sylvia collected 23 disposals to go with his two goals.
With just four rounds remaining, Fremantle sit a game clear inside the top-four after Port Adelaide's six-point loss to Collingwood on Sunday.
And although the Dockers sit a game adrift of the top three teams, they can leapfrog their way into the top two if they can beat Geelong and Hawthorn in the run home.
