Manchester United could be without both Wayne Rooney and Robin Van Persie when they host Tottenham Hotspur on new years day.
Robin van Persie has missed the last five games with a thigh injury, while Wayne Rooney missed the 1-0 win over Norwich with a groin problem.
Wednesday's visit of Spurs will come too soon for the Dutchman, but Rooney will face a late fitness test.
"We'll need to wait and see with Wayne," Moyes told reporters at his pre-match press conference.
"He didn't train (on Monday) so we'll assess it and see how he is
"Robin's not quite ready but we hope he'll not be too far away."
Moyes has been linked with two of his former players in Ross Barkley and Leighton Baines but admitted the January transfer is a tricky time to buy players.
"We'll always be looking to add players if we can but I've said before, I'm not sure that January's a brilliant month to do business," Moyes added.
"It is not normally a month when the players you would choose to get will be made available by their clubs. I won't do business for the sake of it."
Victory against Spurs would extend a winning run to seven matches but the Scot played down his side's recent upturn in form.
"I don't think anyone's jumping up and down because we've won six games in a row - it's expected here," he said.
"Tottenham are difficult opposition. They've either been in the Champions League or they've been pushing for the Champions League and have always been a good, strong team."