Champions' League: Arsenal's new back four - or rather new back five - have dream in safe keeping

Wenger's case for the defence has critics eating their words as stunning run continues

The clean sheets with which Arsenal dazzled first Real Madrid and then Juventus have been worthy of a soap-powder commercial. Their origins can be traced back to a rather less glamorous setting than the Bernabeu or the Stadio delle Alpi. On Saturday 4 February this year, the north London side arrived at St Andrew's to play Birmingham City amid what one newspaper called "the first major crisis of Arsène Wenger's era". Defeats by Wigan, Everton and Bolton had suggested a worrying lack of resolution in the face of North-western steel; worse - far worse - West Ham had just been to Highbury and scored three goals as Sol Campbell, responsible for two of them, quit on his dressing-room stool at half-time.

No fewer than seven other defenders were unavailable for the following game, which made Campbell's abdication from his kingdom all the more reprehensible. Short of asking Pat Rice, Steve Bould and Martin Keown to join him in peeling off their coaches' tracksuits, Wenger (on his own admission a former right-back of no great distinction) could do nothing other than call on a back four of Mathieu Flamini, Johan Djourou, Philippe Senderos and Sebastian Larsson.

The outfield substitutes were of necessity all midfielders and forwards, since no other defensive players could be found. But this enforced mixture of cosmopolitan kids, their average age about half of Jens Lehmann's behind them, did the club proud in keeping Chris Sutton, Emile Heskey and Mikael Forssell goalless during a 2-0 victory. Crisis over. As Wenger remarked afterwards in characteristically dry fashion: "We've shown that everyone buried us a little too quickly."

In 11 subsequent games only four goals have been conceded, the stellar talents of Madrid and Juventus failing to claim a single one and thereby enabling Arsenal to establish a new Champions' League record of eight successive shutouts. Kolo Touré, now the old man of the back line at 25, and Emmanuel Eboué, 22, returned from the African Nations' Cup to replace Djourou and Larsson, with Flamini, the right-footed midfielder, switching to left-back in the continued absence of Ashley Cole and Gäel Clichy. Now the talk is of whether Eboué or Senderos, both outstanding again in Turin last Wednesday, could possibly be dropped for the previously entrenched Lauren or Campbell.

It is difficult to decide which of the current quartet has been the greatest revelation. Make that quintet, since the accomplished Lehmann has won over as many doubters in this country as in his own, Jürgen Klinsmann's watching brief for the Juventus game providing final confirmation that he should be confirmed as Germany's first-choice goalkeeper for the World Cup ahead of a furious Oliver Kahn. There was a flash of the old anger when Lehmann rushed over to confront Pavel Nedved following the Czech's second bad foul on Eboué, but even that could be interpreted as an act of paternal concern for his stricken young right-back.

Senderos, 21, was picked ahead of Campbell for the FA Cup final a year ago, only to find himself a Carling Cup player again in the autumn, but he is finally developing into the centre-half Wenger always promised he would be. "Before the [Juventus] match, the manager told us not to be intimidated but to play our game as we know we can," he said. "We tried to defend as a team and stay compact, and that paid off in the end. Now we must beat Villarreal to go to the final, but we can't say we're playing a little team, because they've proved their worth in knocking out some big clubs." None bigger, however, than Juventus, whose strikers David Trezeguet and Zlatan Ibrahimovic were reduced over two games to figures of ridicule, Continental news- papers competing to award them them the lowest marks out of 10. (L'Equipe's man offered three and three-and-a-half respectively).

All credit, too, to Touré for assuming the senior role so impressively following Campbell's disappearing trick. Wonderfully athletic, and a shrewd reader of the game, he has quickly become the defensive organiser. "But Senderos too is doing really well," he insisted. "We work together and help each other, keeping closely in touch. They are also working really hard for us up front, which makes it easier for us at the back. We play as a team and maybe that's the difference."

Flamini, 22, offered another reason for the improvement: the work done by the old warrior Keown, who has been helping coach the defence. "He's there with us in training and talks to us, passing on his experience. We're playing a lot of games now but we feel fine and it's important we rest between games."

There is increasingly little opportunity to do so. After the trip to Manchester United today come Portsmouth at the other end of the country on Wednesday, then a home game on Saturday against West Bromwich Albion. Next Monday's return to Manchester to play City has been put back to allow a couple of days' grace before the home leg against Villarreal, the two legs of the semi-final spanning a potentially decisive derby with Tottenham in the chase for a top-four Premiership place; as they then face the last three League games in seven days (1-7 May), Arsenal will not want to be under undue pressure for points.

At least the rush of fixtures will allow a certain amount of squad rotation, which is Campbell's best hope of a return to the side, perhaps as early as Wednesday at Fratton Park. Apart from needing to win over Arsenal's manager and many disenchanted supporters, he must offer Sven Goran Eriksson something other than verbal assurance of his mental and physical readiness for a World Cup. Remarkably, and uniquely, Campbell has not missed a minute of England's 16 matches at the last four major tournaments - a record now in the severest jeopardy.

"I'm relaxed about the situation," he said after sitting on the substitutes' bench in Turin. "The spirit is up. I'll get a few games under my belt and be OK. I've been there, seen it, done it, I've done a lot of things for England and I'd do anything to play for England. That's how I play and my years of experience have proved that. And I want to win for England.

"I want to play a couple of first-class games for my club at least. There's a long way to go and a lot of games to go, and so I'm just going to stay calm and wait for my chances. The team's winning and I fully understand it."

Still, however, he will offer no explanation for walking off the job on that strange night at Highbury, beyond a series of vague accusations presumably directed at various media outlets and those who talk to them: "There's a lot of people who have their own hidden agendas, who want to play their games. It's a shame but it's starting to be a big part of football, there's continual lies and talking crap all the time and not allowing someone to play football."

It is tomorrow's people, Touré and Senderos, preventing him now. Seen it and done it or not, they may yet deny him more than an FA Cup final appearance.