Is the fact he performed during a handful of CL games "proof" he is going to be a good player for us or even at this level? History is littered with players that had a good tournament, a good world cup, a good anything. I would say it is only proof that he was a good player for Ajax for that period (and possibly for his entire Ajax career - few except Dutch fans would probably know)
A handful of appearances even if they are at an impressive level are scant proof of anything when the reality is he needs to be good enough week in week out for Man Utd.
It's proof that he can and has played to a higher level.
Is it proof that he can survive long term in the premier league? obviously not - but he needs more than 1 game every month to prove that. It'll come to the point where he either plays regularly and is or isn't good enough, or he doesn't play enough and wants to leave to continue his career.
For me he has all the technical and mental foundations to be a great footballer, but does he have the physical capabilities and the self confidence to adapt and thrive.
Fred had the benefit of getting alot of game time because we more or less had noone else to use there.
VDB wont have that luxury, and without enough game time its much harder yeah.
That is true, but injuries do happen. Ole needs to have confidence in him though and give him a chance. IF say Matic leaves this year, and then Fred or Mctominay gets injured, he needs to put Donny into CM instead of pushing Pogba back. Only once he gets a run of games can we truly say he's just not going to cut it.
If we look at his first half performance he did a fine job, 1 or 2 little mistakes but nothing for people to shout "awful, sell!".
2nd half the whole team suffered, clearly the gas ran out of the whole front 4 and we got penned in. That isn't his fault alone but people look at him in a isolated situation and say he didn't do enough?