In the PL, Fraser needed/needs to be at 100% to be effective. Chasing down everything, getting into tackles, that was when he really shone. Such is the level of player he is relative to the opposition, when even slightly distracted, he will struggle (or at least not be a guaranteed starter)
A player of Josh King's ability in the Championship, that's another matter. I could well understand it's not exactly what he had in mind for this year, but if he's contracted and fit you'd have in the side any day at this level.
It might just take a few goals before the window shuts to spark some interest and get him a move anyway. And if not, stick at it until January and revisit the situation. That's the way you'd have to motivate him I think.