Rob Jones has suffered yet another injury setback.
The 35-year-old has been out since September but had hoped to return to action this month after undergoing knee surgery.
Rovers’ skipper’s comeback remains on hold, however, and he was due to see a specialist this week after breaking down in training.
Boss Paul Dickov said: “Rob’s having problems with his knee. It’s a frustrating time for the big man.”
Jones, who faces a battle to oust first choice centre back pair Andy Butler and Luke McCullough, had pencilled in a return to action in this month’s reserve team fixture against Gateshead on December 3.
“He wanted to play in the Under 21 game [against Gateshead] but we both came to the mature decision it was probably right for him to miss it,” Dickov said earlier this month.
“He’s been training, and training well, but every now and then it flares up and gets a bit sore.
“We’ll nurse him through this.”
Jones missed the majority of last season with a neck problem.
He started this season alongside McCullough but has not featured since limping off against Bristol City in September.
Jamie McCombe was also due to see a specialist this week after tweaking his knee in training.
Dean Furman also remains a doubt for this weekend’s trip to Swindon with a niggling groin complaint, but Nathan Tyson (calf) is in contention for a return.
Dickov, meanwhile, urged his team to ‘stay strong’ after Saturday’s disappointing home defeat to Gillingham.
The 2-1 reverse means Rovers are yet to win at the Keepmoat Stadium since September 20 and have still won just once on home soil since March.
“We’ve got to keep going. We’ve got to be strong,” said Dickov.
“The players have got to have a desire about them to blank everything else out.
“The majority of the performance on Saturday was good. If you’re not creating chances, you tend to worry a bit more.”