Ndong became Sunderland's record signing in the summer.
Ndong signed for £13.6 million in the summer from Lorient and the 22-year-old has played every game since coming on as a substitute in the 3-0 defeat to Everton in September.
Moyes is quoted in the Chronicle, commenting on the Gabon international, saying: “Didier is just beginning to settle in a bit more.
“It is not easy to come in, especially in the position we are in. I think he is finding his feet. I thought he started very well then had a dip.
“At the moment we are not sure where the rollercoaster is with Didier but I do see signs of him getting better. I think his understanding is getting better."
As is the case with any young player, there are likely to be highs and lows; the elements of inconsistency that can only really be ironed out with more game time and experience.
They must have plenty of belief in him at the Stadium of Light for Ndong to become their record transfer in the summer. Moyes' hand may be forced a little in terms of the game time has to give Ndong given the catalogue of injuries they have had in the heart of their midfield so far this season, so he cannot really manage his game time too much. That said it does suggest he has plenty of faith in the player to improve as the season goes on.
He is still a young player with his best years ahead of him and if he grows in his role within the side - in terms of responsibility too - then his first season could end up being a valuable one in terms of the making of Ndong as a player.