The on-loan England Under-19 captain turned an ankle during the second half of Saturday's 1-1 home draw with Pompey and is a doubt for his country's friendly with Turkey on Thursday night.
Lundstram linked up with Noel Blake's Young Lions on Sunday and the teenager will be assessed by England's medical staff.
A more pressing concern for Rovers is that they have reached an agreement with Everton for the player to remain on loan at the Keepmoat Stadium for the remainder of the season.
Therefore, boss Brian Flynn is keeping his fingers crossed on the medical report, knowing that any serious problem could jeopardise that extension.
"He rolled his ankle when he lost his balance as he was stretching for a ball," said Flynn following Saturday's game. "England will assess him and we will take it from there.
"We are renewing his loan until the end of the season. He will be available for Scunthorpe on Saturday, if fitness allows."