Rovers will discover later today the extent of the injury to Colin Kazim-Richards.
The Turkish international limped out of action on Saturday with an ankle and early indications aren't positive.
"We don't know the full extent yet, he is going for a scan this afternoon," Appleton told Rovers Player.
"The worry is that he could be out for up to two to three months, that is the worry.
"We hope he isn't, we hope it is a few week's job, but even if it's that with all the massive games we have, so it is going to be a massive blow him, to the team and to the football club.