Edwin van der Sar admitted Ajax wanted to keep hold of Erik ten Hag but couldn't stop their manager from joining "one of the biggest clubs in the world".
Manchester United have confirmed the appointment of Ten Hag on a three-year deal, with the option of a further year, and he will take over at Old Trafford this summer.
The 52-year-old has spent the last four-and-a-half seasons at Ajax and is on course to win a third league title this season, although their hopes of a double were ended by PSV Eindhoven in Sunday's cup final.
