Ajax midfielder Abdelhak Nouri has suffered "serious and permanent" brain damage after collapsing over the weekend, the Dutch club said Thursday, dashing earlier hopes the promising prospect would make a quick recovery.
"Ajax are deeply saddened by the news that 'Appie' Nouri has been diagnosed with serious and permanent brain damage," the Amsterdam club said in a tweet.
Ajax had said Tuesday a preliminary scan and other neurological tests had not detected any anomalies, and that 20-year-old Nouri would be gradually awoken from an induced coma for more detailed examinations.
But the club "received really bad news" on Thursday.
"The intensive care unit in Innsbruck have examined Nouri's brain functions over the last few days," Ajax said in a statement.
"The diagnosis showed that a large part of his brain isn't functioning any longer and that the chance of a successful recovery of these crucial functions is zero," the club said.
Nouri most likely suffered a lack of oxygen when he collapsed on Saturday during a training match.
The Amsterdam-born midfielder, who is of Moroccan descent, suffered irregular heart problems in the pre-season friendly against German side Werder Bremen in Austria.
After his collapse the player -- one of Ajax's up-and-coming prospects -- was resuscitated and flown by helicopter to a hospital in Innsbruck.
It is expected that he will be flown to an Amsterdam hospital shortly for further care, the club said.
"Abdelhak is such a big talent, but alas, we will never know how high his star would have reached if this had not happened," said former Ajax and Manchester United goalkeeping legend Edwin van der Sar, adding the team had been "hit hard" by the news.
Footballers and fans have taken to Twitter to send the young midfielder their best wishes, under the hashtag #StayStrongAppie, with dozens more messages Thursday afternoon.
The hospital says his family "are taking enormous strength in the many messages of support" and added they have called on fans "to pray" for the young footballer.
"Our thoughts and prayers go out to him and his loved ones is this difficult time," Ajax added.
Nouri made his debut for Ajax in September last year in a Dutch Cup match against Willem II, scoring a goal.
He was also named the 2016-17 player of the season in the Dutch second tier while turning out for Jong Ajax, the Amsterdam giants' reserve team.
Dutch Health, Welfare and Sports Minister Edith Schippers sent her best wishes on Thursday saying it was an "unexpected blow to Nouri, his family, his friends and his team."
The tragedy comes just after the death of 30-year-old Ivorian international Cheick Tiote, who died in China in early June after collapsing during training with second-tier club Beijing Enterprises.
Cameroon international Patrick Ekeng, 26, died of heart failure in May 2016 after collapsing during a league match while playing for Dinamo Bucharest in Romania.