Aston Villa manager Gerard Houllier was on Thursday being treated in hospital after he fell ill on Wednesday evening.
Premier League managers quickly sent 'get well' messages to the Frenchman, whose condition is described as comfortable. The 63-year-old underwent open heart surgery in October 2001 after feeling unwell when Liverpool boss during a match with Leeds and did not return to full-time management for five months.
The exact nature of his current illness has not been revealed, but he will undergo tests and remain in hospital for a number of days. Assistant manager Gary McAllister will take charge of Villa's home clash with Stoke at the weekend. A Villa statement read: "The club can confirm that Gerard Houllier was admitted to hospital last night."
It added: "He is in a comfortable condition and he wishes to convey his appreciation to Aston Villa supporters for their concern and good wishes. The manager spoke to chief executive Paul Faulkner this morning and he is currently undergoing tests. It is anticipated that he will remain in hospital for several days.
"Assistant manager Gary McAllister has taken training this morning and he will be in charge of the team for the game against Stoke on Saturday at Villa Park. The club's thoughts at this time are with Gerard and his family."
Houllier had undergone a routine check-up with Villa's medical staff last week, but at 7am this morning contacted Villa's chief executive Paul Faulkner to allay fears about his health. Faulkner and McAllister were due to visit Houllier in hospital today.
Houllier has endured a demanding first season after replacing Martin O'Neill in September. He has come under fire from some Villa fans on a couple of occasions and sections of them have called for him to be sacked.
But results have improved in recent weeks with Villa climbing into the top half of the Barclays Premier League after taking seven points from the last three games. Faulkner said: "On behalf of the football club, Randy Lerner (the club owner) and I wish to convey our best wishes to Gerard.
"I spoke with him this morning, as did Gary (McAllister) before he took training, and he sounded very positive. I've also received a lot of good wishes from fans and I would like to thank them for their kind thoughts in wishing Gerard a speedy recovery.
"I will see him this afternoon, along with Gary, and we will pass on the fans' messages. I know they will mean a lot to him. We would ask everybody to respect his privacy and that of his family at this time."