Manchester United legend Edwin van der Sar says Chelsea No1 Thibaut Courtois is on track to be the world's best.
Ajax chief Van der Sar is expected at Old Trafford tomorrow.
He said: "Courtois' progress hasn't surprised me. He has performed fantastically, when you see what he has already achieved at his age - I was already 23 when I got into Ajax' first squad.
"You have to admire him because he has convinced Jose Mourinho to pick him above Petr Cech - it must have been a difficult decision to push a legend like Cech aside."
