United chief executive David Gill has confirmed that negotiations with Partizan Belgrade duo Zoran Tosic and Adem Ljajic are still in progress.
The Reds have been granted a work permit for Tosic, but personal terms are yet to be agreed. Discussions with midfielder Ljajic are also continuing.
"We're still in negotiations with both," Gill confirmed to MUTV. "We've agreed club terms, now we're working on the player terms. They may or may not happen.
"Apart from those, I don't think there will be a lot of activity from us in January.
"Perhaps the odd loan signing going out if Alex decides he wants to give some of the younger players senior experience elsewhere. But I don't expect there'll be much else."