Roy is expected to return from holiday today and any appeal against the punishment imposed by an FA tribunal two weeks ago has to be lodged within the next 24 hours.
It means he will miss five games during the next month and pay a £150,000 fine with the ban due to start on Monday week and a targeted return date of Arsenal at home.
Sir Alex Ferguson has said that he is unsure what steps Keane plans to take, but feels he has decided not to take the matter any further.
"It is Roy's decision. I have heard nothing. There is not much time left and he would need to let them know on Monday. I would have thought he would have let me know by now if he was going to appeal."
"Roy was away for a week with his wife and kids in the school holidays and when he comes back we will assess things to see when he can start on the football training. I think that will be in the next two weeks. He is in great nick, there are no worries about that with him, he's fine," added Ferguson.