Andy Bulumakau is struggling to be fit for Sunday’s trip to Cornish Pirates.
The centre linked up impressively with Mat Clark in last weekend’s impressive win over Yorkshire Carnegie but picked up a knock in the closing stages of the game.
Clark himself was returning to the starting XV following a lengthy injury lay-off, Tom Davies also returned to the fold, while Ume Fosita made an eye-catching debut at fly-half.
“It is good to have players vying for position but the bad news is it looks like Andy is injured and, at this stage, looks doubtful for Sunday,” said director of rugby Clive Griffiths.
“That is a shame as he and Clarky played well outside Ume at ten.
“It’s part of the game but it is frustrating when you cannot keep a settled combination together from one week to the next.
“As coaches you love and hate selection headaches, it is the hardest part of the job telling players they’re not playing but it is a necessary part of the job,” he added.
“A lot of boys put their hand up on Saturday as part of a fantastic all round performance.”
Doncaster have beaten the Pirates twice this season in the B&I Cup but lost the corresponding league fixture.
“We can take heart from knowing that we’ve already been there, given them a 20-point head start, and come back to win,” said Griffiths.
“We’ll need to be squeaky clean and not allow them the penalties to get their driving game going which will be a massive part of their game plan.”