Sander Westerveld's dramatic plunge from favour will be completed this afternoon when the Dutch international fails to make the Liverpool bench for the visit of Aston Villa to Anfield. With Jerzy Dudek making his debut and the other new signing Chris Kirkland still recovering from a ligament strain, Pegguy Arphexad will forgo a loan move to Portsmouth to undertake substitute goalkeeping duties.

Unsurprisingly, Westerveld is not considered to be in the best frame of mind, scarred as he is by his descent from first choice to outcast in the blink of an eye - the split-second in which he lost sight of Dean Holdsworth's innocuous shot at the Reebok stadium 12 days ago proving decisive.

"This is a warning to everybody in the side," said the Liverpool manager Gerard Houllier, who shed his hitherto gentilhomme image by signing Dudek and Kirkland in the wake of his side's first defeat in 16 games. "Our target is to win. I know it looks ruthless and my heart goes out to Sander - he's a nice guy and helped us win the treble last season.

"But if you get a bit sloppy or are not putting enough energy both mentally or physically into the team, then your place in the squad is jeopardised."

As demonstrated by Phil Thompson's recent spat with Robbie Fowler, which had briefly threatened to derail the Reds' resurgent bandwagon, Houllier's priorities lie firmly with the wider picture rather than personal loyalties. Fowler the Kop icon was forced to back down; Westerveld, even bolstered by an outstanding display in the recent Charity Shield, was not deemed up to scratch.

"If I think I have to change things for the good of the team, that's what I will do in any area of the side," said Houllier. "I told Sander that either he becomes better or I would buy a new goalkeeper because I want to win the title. To do that you have to have someone who is good and consistent.

"Goalkeepers are not assessed on the number of saves they make, but on the few mistakes they make and the points they win for you. I wanted to improve an area which needed improving. Sander's a professional and his attitude has been irreproachable since he returned from Holland.

Westerveld will at least be able to seek solace from his close friend and compatriot Edwin van der Sar, who suffered similar disappointment at Juventus over the summer when the Turin club spent £33 million sterling on Parma's Gianluigi Buffon. Van der Sar promptly joined Fulham.

Houllier's warning also applies to Dudek. The 28-year-old's shaky performance against Belarus midweek - he was at fault for two of the goals in Poland's 4-1 defeat - will hardly have done his confidence any good. "It's been busy and will be just as hard against Villa," he said. "I'll be a little bit nervous, but it's sweet to play for such a great club as Liverpool."

Houllier failed to have his £4.85 million sterling signing excused the trip to Minsk as Poland's qualification for the World Cup was already guaranteed. "I thought psychologically he would not be right what with the transfer," he said. "I was proved right.

"But we have two outstanding talents here. I've always wanted to keep a British heart to the team and Chris could be the next England goalkeeper. We signed Chris with long-term objectives in mind; Jerzy's the present."

Westerveld is clearly the past.