I don't want him to play for United for reasons I've stated in other posts before, but on a purely football perspective, I can't see how he'd really play for us this season anyway in any meaningful way considering how long he's been out of the game.
The other thing, which I think is more important, is that I think it'd be too much of a distraction to our season preparations. There'd just be too much focus on him being back, it'd distract the squad, and I also think there would definitely be players among the squad that wouldn't want him back, just like how it's so divisive among us fans. But that's going away from the football side of things slightly.
So I think he'll definitely go on loan if we can get him one. It's the best middle ground decision for the moment.