The Old Trafford club, who face table-topping Arsenal on Sunday, have internationals Nemanja Vidic, Rio Ferdinand, Phil Jones, Chris Smalling and Jonny Evans to choose from in their back line.
And Moyes confesses finding consistency in the centre of defence is proving a challenge as he tries to keep all five happy.
"You would like to have a bit of continuity but when you have five centre backs like we have here in the squad they all need to be used," he said.
"They all need to be played at different times, and some of them have had injuries which have meant we have had to change.
"It would be better if we could get a bit more consistency to it but, at the moment, whoever we have brought in has done well."
However, Moyes does admit that being spoilt for choice at the back does have its advantages.
"I am pleased because if we can tighten up at the back, the quality of players we have got in the forward areas tend to make the difference," he added.
"So I am pleased that in the last couple of games we have looked a little more solid, and more likely not to concede so many goals."
