And he knows only the best will be good enough if the Baggies are to follow up their quarter-final win over Manchester United with another famous victory tonight over Arsene Wenger’s Arsenal.

Megson said: “Whether there are changes in the team or in the way we defend, something has got to happen.

“We gave away two slack goals against Crewe on Saturday and I expect much better from my players.”

For all their divisional dominance, Albion have not won a home league match in five attempts with only the thrilling success over United lifting the gloom.

And Megson will be keeping his fingers crossed that inspirational midfielder Jason Koumas is available after missing training with a hamstring strain yesterday.

Defender Darren Moore is back from flu, while Neil Clement should replace the Cup-tied Paul Robinson at full-back.

Megson knows the Gunners are likely to field a youthful side, but refuses to get complacent having seen how a so-called below-strength United line up in the last round.

He added: “We’ve probably not played against a good a midfield so far this season as United put out that night.

“They had Ronaldo, who is a very expensive young player, Nicky Butt, who is in the England team, Darren Fletcher, who would get into most sides and Kieran Richardson.

“Although these huge clubs do sometimes rest their best players it’s relative to anybody else in terms of the size of their squads and their quality.”

Meanwhile, the Baggies confirmed they have reached a deal for Wigan striker Geoff Horsfield.

The former Birmingham forward was due to open talks at The Hawthorns today, but would not be eligible for the Carling Cup tie even if a deal was rushed through.