No desire to train Maybe 20ibs over weight Demanding schedule Demanding Relationship No longer following boxing closely Still wants to fight and train just cant find the fire
Get him a fight/competition to train towards. Take it easy for a bit, focus on some different sort of cardio, conditioning, without being boxing related particularly. Boxing is not a pick up and play sport (you probably know this!) so the most important factor here is that there is no desire to train, that's the be all and end all. If he knows anything he knows if he doesn't want to train there is no way he can fight. "The fire" doesn't have to be a big deal, you train because you want something that requires time and dedication and you accept. If he doesn't really want it, he can make all sorts of excuses that "the fire is not there", what does that even mean.
Ban him from the gym, tell him to take it easy. If he still has the desire he will come back when it rekindles, if its gone its time to stop anyway.
Thats alright, tell them to take time off. Most fighters always get back into it when the time is right. I wouldn't recommend half ass training if the hearts not into it. Does more damage than good.