Newcastle United academy director Steve Harper is "awake and recovering well" after suffering a stroke on Monday.
The 48-year-old former goalkeeper played 199 times for the Magpies between 1993 and 2013.
The club confirmed he suffered a subarachnoid haemorrhage, which the NHS website says is an uncommon type of stroke caused by bleeding on the surface of the brain and can be fatal.
"Steve will be given the club's full support as he recovers," United said.
"Steve, his family and everyone at Newcastle United extend a heartfelt thank you to NHS staff for the incredible care he is receiving.
"Everyone connected with Newcastle United send their best wishes to Steve and his family as he continues his recuperation."
Harper is the longest serving player in Newcastle's history, with a 20-year spell - joining them in 1993 as a teenager and staying until 2013 when he joined Hull.
However, he played only 199 games during that time as he largely served as back-up goalkeeper to Pavel Srnicek, Shaka Hislop and Shay Given.
He was named Newcastle's full-time academy director in 2021 after various other coaching roles with the club.
Our coverage of Newcastle United is bigger and better than ever before - here's everything you need to know to make sure you never miss a moment