The 'Gers striker appeared to damage knee ligaments in the weekend's 2-1 win at Aberdeen although scans due for today will show more.
However, Davis is looking at a worse case scenario and just hopes his mate can return from the mishap as well as he did from his previous knee injury in 2008.
"It's a massive blow for the whole team as well as him personally," he said. "Last year he was player of the year and he has been fantastic so far this season. It puts a real dampener on the result.
"Everyone around him will support him. He did his other knee before and came back fitter and stronger than ever.
"Over the last 18 months he has possibly been our best player so that tells you how much of a blow it is going to be to us. Hopefully he can bounce back."