Former Newcastle goalkeeper Pavel Srnicek is in a critical condition in hospital after suffering a cardiac arrest.
The 47-year-old, who made 150 appearances for the Magpies between 1991 and 1998, collapsed while out jogging in the north east on Sunday night.
His agent Steve Wraith wrote on Twitter: "I can confirm that Pavel has suffered a cardiac arrest whilst running and is in critical condition in hospital.
"Pavel was running last night and his heart stopped he was like that for 20 minutes then rushed to hospital he is an induced coma until wed.
"then they will see if his heart is stronger and if so bring him out of the coma.....no one knows if his brain has been to starved of oxygen".
The Czech Republic international also had stints with Sheffield Wednesday, Portsmouth and West Ham before making a brief return to Newcastle in 2006.
He is in the north east to promote his autobiography, "Pavel is a Geordie".
Newcastle were quick to offer a message of support, tweeting: "Our best wishes go to @PavelSrnicekUK, who has been taken to hospital today. Get well soon, Pav. #NUFC".