When asked in a press conference if he will be looking for new players in the winter window, Moyes said: "Only if the right players are available. They have to be able to fit into our squad. We would like to but there are no guarantees."
Moyes was also prompted about a potential return bid for Everton full-back Leighton Baines, but the Scotsman responded: "If they are determined to hold on to him then he can't be going anywhere."
United are preparing to take on Tottenham Hotspur at White Hart Lane on Sunday.