Nouri was treated on the field during the game — which was subsequently abandoned — at Lindenstadion in Hippach, Austria, before a trauma helicopter arrived and the 20-year-old was taken to hospital.
Although Nouri recovered a stable heart rate and Ajax confirmed on Monday that his heart was functioning normally, doctors were unable to examine his brain until he was brought out of an induced coma.
Our thoughts and prayers go out to him and his loved ones in this difficult time. (2/2)#StayStrongAppie— AFC Ajax (English) (@AFCAjax_EN) July 13, 2017
On Tuesday, the hospital in Innsbruck were "cautiously optimistic" after a CT scan and other neurological tests did not show any abnormalities but Ajax have confirmed the latest tragic developments.
"Ajax are deeply saddened by the news that Appie Nouri has been diagnose with serious and permanent brain damage," read a statement released via the club's Twitter account.
"Our thoughts and prayers go out to him and his loved ones at this difficult time."
Ajax chief executive Edwin van der Sar told the club's website: "This is the worst possible news we could get. It is devastating. Our thoughts are with his parents, his brothers and sisters and the rest of his family.
“There are no words to describe what they are going through. This is a huge blow for Ajax, even if we knew this scenario was a possibility.
“It were some very difficult and insecure days, with a lot of people showing their support. We really appreciate that.
“Abdelhak is such a huge talent, but we will never know how bright his star would have shone had this not happened."