Manchester United new boy Donny van de Beek has been hailed as the "embodiment of pride" that former club Ajax have in their young players.
In an open letter to United supporters, Ajax chief executive and ex-Red Devils goalkeeper Edwin van der Sar asked them to help the Netherlands international "dream".
The 23-year-old van de Beek moved to Old Trafford on Wednesday for Stg34.1 million ($A63m), plus add ons, on an initial five-year deal to become Ole Gunnar Solskjaer's first new recruit of the summer.
Van de Beek played an important role in Ajax's thrilling run to last year's Champions League semi-finals, and came off the bench as the Eredivisie giants lost the 2017 Europa League final to United.
Van der Sar, who spent six years at United before returning to Ajax in a backroom role, has now told fans what an exciting prospect their latest signing is.
"Dear Manchester United fans... It seems our paths have crossed again," he wrote.
"One of ours is joining you this season. And like so many players before him, he's been with us since he was just a little boy.
"Shortly after his debut, he became one of our best. Especially the last couple of years were amazing... The team he was part of showed the world who we are and what Ajax stands for.
"Like you, we pride ourselves on being one of the best at developing talent and giving young players a shot at the highest level.
"You could say your new star is the embodiment of that pride."
Van der Sar signed off by admitting it was difficult for Ajax to let one of their top players leave, but that it was necessary to allow van de Beek to develop.
"We understand it's time for him to move on. To dream on," he added.
Van de Beek completed his move while on international duty, with the Dutch set for a Nations League double-header against Poland and Italy.
"I cannot begin to explain how incredible an opportunity it is to join a club with such an amazing history," he said in an interview with the official Manchester United website.
"I am now ready to take the next step in my career and perform at the highest level and there is no higher standard than Manchester United."