A little bit surprised by this decision.
As I alluded to earlier, he's fairly decent defensively and has been genuinely dangerous in the final third this season. You'd think given those two things that he'd be a good full back but when we need to keep the ball and build from the back, he plays too many many shit passes and hoofs the ball up field too much. Even his hoofs are often shit because he's forced to clear with his weaker left foot.
His deficiencies in this area are probably less obvious when he plays at right back, but he is much better at in-swinging crosses from the left than he is at crossing from the right. Weird player, tbh.
I'd rather just buy a new LB and have Shaw deputise to them/try to win his place back. As it is, Mourinho seems to hate Shaw's guts so if he's off then we could definitely do worse than Young as a second choice left back I guess.