I'd be very surprised, given that he has had a full pre season training if he wasn't far fitter at this moment in time than Rondon.No but Rondon won't be injured for 6 weeks of one tap to the calf. Rondon wants to stay. If you had an unfit James playing its a disaster waiting to happen. However some of the things James can do are world class so if he is fit and wanting to play utilise him.
As to his motivation....that's down to him and the manager.
Some players , especially at elite level are highly self motivated. Other players might need motivation from the manager , that's part of their job. Right now I can't see any reason why James isn't on the bench other than Benitez's arrogance and ego.