Former Celtic and Scotland star Jackie McNamara has been rushed to hospital in England after collapsing on his doorstep.
Friends of his family say the former defender is undergoing surgery with fellow Hoops icon John Hartson saying Jackie has a '"bleed on the brain".
It is understood the 46-year-old was taken to hospital in York and then transferred to another hospital in Hull.
A source said: "He has been taken to hospital to undergo an operation.”
McNamara was manager of York City FC until March 2018.
He is now a consultant with Dunfermline Athletic where his football career began in the early 1990s, though he still has a house in north of England.
A pal said: "Jackie was out walking the dog on Saturday near his home in York.
“He became unwell quite quickly and he headed back to his house.
“But he must have been really poorly because he did not make it back into the house.
“He collapsed on the doorstep and his family found him.
“So this is a really worrying time for his family and his friends.
“We’re just hoping that he can come through this.”
McNamara, who won 33 caps for Scotland and made 256 appearances for Celtic in a glittering career, is involved in various business concerns.
Top news stories today
As well as his consultancy with Dunfermline, he is also an agent and runs a pub in Spain with fellow ex-Celt Simon Donnelly.
The pal added: "Jackie works really hard and has a lot on his shoulders.
“There is also a lot of travelling that he has to do.
“We still don’t know the full facts and we are waiting to hear results of the operation.”
The hospital trust in Hull did not confirm whether the ex-player is a patient at the moment.
Celtic Football Club took to Twitter to offer their support to McNamara and his family.
The club tweeted: "The thoughts and prayers of everyone at #CelticFC are with Jackie and his family."
Fellow Celtic legend Hartson said he was thinking of his "great friend, his wife Jackie and their kids.
He tweeted: "Worried sick for my former teammate and great friend Jackie McNamara who collapsed at home Saturday with a bleed on the brain..my thoughts are with his wife Samantha and the children."
While Chris Sutton said: "Thoughts and prayers for Jackie and Sam and the family."
Jackie's family have been approached for comment.
