The 28-year-old Republic of Ireland international is now three matches into his comeback but Allardyce will be keen not to over-expose him so soon.
Allardyce Concern About Duff!
Damien Duff: "It's been busy, but that doesn't bother me because I'm just delighted to be playing again.
"The results have been disappointing though, especially Chelsea (a 2-1 defeat) when we felt we could have got the win and definitely the draw.
"But I'm feeling great in myself and would say I'm just about 100% fit now.
"I came off with a couple of minutes to go against Chelsea but I felt like I could have run all day.
"Now we have got some big games in the new year and I am looking forward to it.
"When you have been out for so long, you really appreciate playing again.
"We have got another busy month coming up and we have to build on that Chelsea performance and hopefully get a win in front of our own fans against Man City on Wednesday."