Zaha joined United from Crystal Palace over the summer.
The 20-year-old was expected to make an impact at Old Trafford but has yet to make his Premier League debut for United.
A number of Premier League rivals are interested in signing Zaha.
Moyes said in The Sun: "I've said if I couldn't get him a game I would look at it in January.
"I really thought when he came in he needed to be here for six months to see how we work.
"There is competition in the wide areas with Nani, Antonio Valencia, Ashley Young, Adnan Januzaj and even Shinji Kagawa - that makes it one of the areas where we are strong.
"It's not because Wilf has not done enough, it's because we have got big, big competition and there are a lot of players to give some playing time to.
"Unfortunately we've not been able to do that with Wilf. If I can't do a lot for him by January then I will look at it.
"We've not had the right opportunity to introduce him as much as we'd like but he's very much in my plans."