If his body is an issue it'd be weird to entrust him to a different (and, given he'll be moving down a level or two, worse) medical staff and coaching staff. Just keep him here and use him carefully.
Which is why I underlined "consistently"
Young players have been farmed out to the Championship for a very long time... and there is a reason for that- it's less consistently challenging than if they'd play for their parent club, but better than the Reserves/Academy, it keeps them hungry- wanting to improve away from the club, and keeps them loyal to the club(as opposed to sitting on the bench, not getting the games cause of the pressure for results... and having to play a U19 game here and there- a level that isn't in any way a challenge for such a talent).
The standard in the Premier League is quite high and it's because of the need to perform at the highest level, consistently.
Really guys, the Championship isn't some backwater on the Appalachian trail where wounds get treated with the trusty old spit+mud combo, and they get rid of headaches by "drawing" out wicked spirits from the top of your skull.
Plenty of clubs send their best players to the Championship, with agreements in place, the necessary dietary requirements, suggested treatments, and communication between the clubs, as well as regular visits and analyses by the parent club's various staff.
Young players get seriously injured in the Premier League instead- with it's consistent high-octane, high-stakes demands.
What he needs now is a more
consistent challenge than he would get in the "Reserves" and Academy- at a higher level, so that his body gets used to it, grows the necessary bulk, marrow, bone and whatever resistances are needed.
He's already got the brain, the technique and now he needs to learn to apply them more consistently.
He'll get that in the Champo or in some other league in Europe.
Staying here only to get a game now and then, isn't going to be good for him- at least in my view.
I don't wanna see him get hurt again in the near future- I wouldn't be able to stomach it.