The Owls are sweating on the fitness of the striker, who picked up a foot injury earlier this month, and missed Saturday’s 1-0 win over Ipswich Town.
Wednesday boss Darren Moore confirmed the club were waiting to assess Gregory - once the swelling on his foot eased - but the worst-case scenario, a long-term injury, could prompt a late deal before the January window closes on Monday night at 11pm.
“He’s sustained a foot injury that he picked up in the Oxford game, and it’s not a good one… We miss Lee, but in terms of the injury we’ll have to look at it over the next seven days and then we’ll see how it is. We’ll have to assess it.
“We have to wait for the swelling to go down, and it’s a bitter one to swallow. He did it in the first half against Oxford, so credit to him for carrying on, but it’s unwelcome news really.
“We didn’t want to lose Lee, he’s a talisman for us, but we’ll assess him over the next few days and see how he is.”
Owls midfielder Dennis Adeniran’s season is over, after he had hamstring surgery.