The club intervened ahead of the 1 July date when the contract was due to renew for the 22-year-old who collapsed while warming up for a pre-season friendly against German club Werder Bremen in July 2017.
"It is correct that Ajax has terminated Abdelhak Nouri's contract, amongst others," Ajax said in a statement to AFP.
"Ajax did that with all players whose contracts end on 1 July including Klaas-Jan Huntelaar and Ryan Babel," the club said.
Both Huntelaar and ex-Liverpool player Babel are former Dutch internationals.