turkin with a bum foot

sorry in advance if people are getting tired of answering foot questions, but in my hurried searching I didn't find any solid info on the subject and I'm a new flock keeper...
I noticed yesterday my turkin rooster hobbling in the yard. I watched him throughout the day and he wants to move around, he eats and drinks, but he absolutely will not put weight on his right foot. he keeps it pulled up to his body and will put it down when he needs to, but mostly balances or puts down his wing tip. he lays a little sideways because he won't sit on his feet right now, he sits on his knees (are they knees on a chicken?) of course, I brought him inside last night and cleaned his feet. keeping in mind his left foot is fully functional- both ankles are beefier than my Wyandotte's, and the pads of both feet are pretty fat so its not obvious anythingnis wrong, but the right is not noticeably more swollen than the left. the toes are completely stiff, I could barely loosen them up to bend at all. the leg and foot has a very slight black discoloration and the skin is dry and starting to look flaky.
ultimately, my thought was early frostbite because its been close to zero degrees every night here in wisconsin. maybe a sprain? I'm sorry I cannot attach pictures, I would just like some guidance on a closer diagnosis, what I should be looking for, or whatever other help can be given is much appreciated.