1131 GMT April 01, 2020
The Dutch club confirmed that Malen will move after he turned down an offer to extend his stay, eurosport.com reported.
The player then posted a picture of himself on Instagram signing his contract, before deleting it. Not before it did the rounds on social media though.
Ajax head of youth Wim Jonk said, "Donyell is a great talent. It is extremely unfortunate that he is leaving Ajax."
Previously Jonk had told Voetbal International, "We have made Donyell an excellent offer and presented a clear plan for his development.
"If the player still makes the decision [to leave], that's disappointing, because his potential is clear and he would be given opportunities with Ajax. We will continue with the guys who believe in the plan."
Malen is represented by agent Mino Raiola, whose other clients include Zlatan Ibrahimovic and Mario Balotelli.