After a tricky start to his tenure, Moyes has been assured by United's owners that cash will be made available to strengthen his squad.
The problem is top-class players are rarely available during the mid-season window.
It could be a struggle to sign two of the men United bid for in August, even though neither Leighton Baines nor Ander Herrera will be prevented from playing in European competition, as Everton and Athletic Bilbao will have their own targets to aim for.
So Moyes is cautious about building up fans' expectations.
"I'll look at January but I wouldn't want people to have big expectations of what we would sign or do," Moyes told reporters.
"In the main, January has not been a great month to sign at the top level.
"If you're in trouble near the bottom you might as you're desperate for something but we'll be looking for the top players."
Moyes does want to strengthen though.
It was anticipated he would make more reinforcements following his arrival beyond the single, significant capture of £27.5million Marouane Fellaini from Everton in the last minutes of the transfer window.