If that's the case then he should go out on loan. I reckon Moyes will be honest with him about his chances in the first team. The problem is the line needs to be drawn somewhere. A player can't go from a regular in the championship on loan to being first choice in the PL when he comes back, it's a different level. They need to be squad players first unless its a PL team he gets a loan to, like Baines.
Kroupi Jr the 18 year old lad Bournemouth bought tore up the French 2nd division on loan and now he's with the Bournemouth squad as a squad player for the season. Seems like the right pathway, but as you say, depends on the manager too