In-form Keshi Anderson is struggling to be fit for tomorrow’s trip to Millwall.
However, Rovers are hopeful the on-loan Crystal Palace striker could return at the weekend to face Colchester United.
Anderson, whose stock is rising after three goals in six appearances for Doncaster, travelled with the squad to Peterborough on Saturday.
But he could only watch on in frustration as his teammates were put to the sword by Posh.
Boss Darren Ferguson revealed after his side’s 4-0 defeat that the 20-year-old’s foot injury, which he sustained during last week’s win at Shrewsbury, is not as bad as first feared.
“Keshi was nowhere near. He was always out,” said Ferguson.
“He’s very very doubtful for Tuesday as well. We’re sort of pencilling in the Colchester game.
“He went for an X-ray after the Shrewsbury game and there’s nothing broken or fractured, so that’s the key thing.
“We’ll just have to see how he is.”
Anderson was replaced by Andy Williams but, for the first half at least, Rovers offered precious little attacking threat as Peterborough dominated the midfield and had Doncaster penned back for long periods.
Ferguson insisted the defeat, and the manner of it, has not changed his view on the size of the job he faces.
“Nothing’s really changed,” he said. “We’ve got a lot of work to do.
“We’ve got some very good players, but we have to be intelligent enough to get the best out of them and use them in a game.
“We need to show more composure and we need to keep the ball better.
“I didn’t want the game to be stretched, I didn’t want the game to game to be open. It suited them.”
Ferguson, Peterborough’s most successful ever manager, was given a good reception by home fans before the game.
“I got a great reception and I was really pleased with that,” said Rovers’ boss.
“It was probably the only good thing that’s come out of the day.
“I appreciate that because I had a really good time here.
“It’s a good club and nothing that happened [on Saturday] was going to change my mind on that.”