Aston Villa have confirmed manager Gerard Houllier will miss the club's final four Premier League matches of the season.Houllier, 63, is under observation after complaining of chest pains last week, and the Frenchman previously endured major heart surgery in 2001 while in charge of Liverpool.

Houllier was absent from the touchline for Villa's 1-1 draw at home against Stoke on Saturday, and his assistant Gary McAllister has been placed in charge of the team until the end of the season.

Villa director general Charles Krulak said the priority was for Houllier to get well without the pressure of management.

"It is serious, something that we have to be concerned about," Krulak said.

"I am afraid he will not be on the sidelines for the remainder of our games. The key is his health and that he recovers completely."

McAllister, a former manager at Leeds and Coventry, said he will have no problems stepping into the role but concedes he is relatively inexperienced.

"The facts are I'm a professional man. I'm the number two and when the manager is not here, I've got to go in," McAllister said.

"I'm fortunate I've managed another big city club in Leeds and another not far away from here at Coventry."

"I'm trying to get better at knowing the character of the modern-day player."

"My experience is not massive. My main experience is coming from being an ex-player."

McAllister said he was unsure when Houllier would return to work.

"We are very much in the hands of the specialist. There is a lot of monitoring going on, there are loads of machines in and around Gerard," he said.

"As far as I am concerned, the way I see it, it is a bit early to suggest the length of time he is going to be in there or what the next step is."