The former Valencia midfielder has been sidelined since August with a thigh tendon injury but is stepping up his training.
However, manager Gus Poyet does not want to put a precise timescale on his return.
He told the Argus: "It doesn't need to be in January, it could be in December.
"I won't have a problem if he can play on the 29th or the 22nd. If that was the case it would be great.
"He has been training last week, but with us, I don't know. He has been training more than he was a month ago.
"He has been working on his fitness in different ways, a different programme so that he can get better and maybe join the group.
"He has been doing a bit of everything, strength work, controlled training, running, the new gravity treadmill and plenty of pool exercises which could be really hard but not the same as playing.
"It is a different way of bringing him back to the first team quickly, where he can train and forget about everything. I don't want to put a date on it, because that's not fair."
- Sports & Recreation