Was it just honest dungarees football or, as the coach and players of Barcelona suggest, more the kind of behaviour to be expected from men in battlefield fatigues? What is certain is that the remorseless negativity of Chelsea’s performance at the Nou Camp last week leaves them with an obligation to prove it was merely a pragmatic preamble to turning destructively positive at Stamford Bridge on Wednesday night.

Reliance on grinding efficiency and on exploitation of superior physical power gave them goalless equality in the first leg of their Champions League semi-final. Now there is no option but to demonstrate that their ability to smother talent is matched by their capacity to flourish it. If they can’t do that convincingly enough to reach the most important club final in world football for the second year in a row, all the English sneering about Catalan whingeing will sound a little hollow.

Already it strikes a hypocritical note. Does anyone believe that if a team from abroad had come to this country with no serious trace of ambition beyond application of the bruisingly disruptive methods to which Chelsea devoted their energies last Tuesday the sports pages here wouldn’t have carried headlines as sour as those quoted so scornfully from the Spanish papers? Andres Iniesta, Xavi Hernandez and others may have overdone the grousing but they did have grounds for complaint. If they were hardly subjected to a battering, they were frequently roughed up and illegally denied the benefits of their guile. Even the leniency shown towards Chelsea by the German referee, Wolfgang Stark, did not prevent them from being penalised for nearly three times as many fouls as the opposition (20-7).

Obviously, teams concentrating on defence foul more than attackers but Chelsea’s offences often seemed born of calculation rather than desperation. Their legitimate protection of their goal was a triumph of alertness and organisation — when John Terry’s masterly marshalling of the unit in front of Petr Cech looked liable to be insufficient, the goalkeeper himself was ready with inspired saves — but questions of legitimacy sometimes seemed marginal in the collective determination to thwart Barça. That there is still rather a lot of thwarting to be done is emphasised by the insistence of so many bookmakers on keeping the Spanish champions as fractional favourites to win the tie. The tiny margins in the betting framed for the collision in west London provide a sharp contrast with the odds offered for the second leg of the Arsenal-Manchester United semi-final at the Emirates stadium a night earlier. United are generally 3-1 on, while Arsenal can be backed at 12-5. The one goal Sir Alex Ferguson’s men scored at Old Trafford last week has also had the effect of putting them a mathematical sliver ahead of Barcelona as favourites to be crowned European champions in Rome on May 27.

As Chelsea ponder their prospects of making a mockery of all that predictive accountancy, the encouragement of having become the first opponents this season to prevent Barcelona from scoring at the Nou Camp is bound to be tempered by heavy awareness of how much more difficult it will be to preserve a clean sheet against the most vaunted attacking force in football when there is the necessity of doing damage at the other end of the park. Still, the players must draw optimism from the memory of how comprehensively Guus Hiddink’s tactics and their own sweaty rigour imposed a torture of frustration on the usually mesmerising Lionel Messi and his glittering supporting cast.

Barça created enough chances to demand an exceptional contribution from Cech but they never threatened to overwhelm Chelsea, never went close to achieving the level of sustained pressure with which United besieged Arsenal in the first half at Old Trafford. For Chelsea, the strain in Spain was far less intense than the majority of us had imagined it would be. The same cannot be said of the hardships of the spectating experience, even as diluted by television. Of course, if the pick-and-shovel football that gained the 0-0 scoreline turns out to have been work on the foundations of a towering performance at the Bridge, its validity won’t be challenged. But if Chelsea settle for trying to edge to Rome by means of a muscular conservatism — if, say, they rely too often on aiming long balls towards an isolated Didier Drogba — it will be an insult to the range of gifts they possess.

Drogba, clearly, will be a key weapon. He is every time he goes on to the pitch and the Barcelona central defence, never especially impressive and further weakened as a result of significant removals by injury and suspension, could well find his combination of heavyweight athleticism and precise skills unplayable if he is given the right kind of service. His teammates should seek to ensure as much with the concerted, surging counter-attacks that are always crucial to their most effective displays. Professionals constantly tell us that in semi-finals quality of play never matters, that nothing counts but survival, the avoidance of anti-climax. It’s hard to argue with that attitude. Yet somehow it doesn’t seem too romantic to ask of Chelsea that they not only beat Barcelona but do so with sufficient style to make the worldwide football public recognise it as just that such as Terry and Drogba, rather than Messi and Iniesta, are in the final. That amounts to a tough wooing of popular sentiment but it’s not beyond Chelsea. As for the other semi-final, if non-partisan opinion were polled the probable outcome would be a consensus that Arsenal and Manchester United have equal claims to being considered desirable participants in Rome. A vibrant showdown is promised.

As I head into the Stadio Olimpico three-and-a-half weeks from now, it will be with the hope that the contenders soon to take the field can inhabit the creed expressed by the mighty Jock Stein shortly before he led Celtic to British football’s first victory in the European Cup 42 years ago. “We can be as hard and professional as anybody,” Jock told me, “but I mean it when I say we don’t just want to win this cup. We want to win it playing good football, to make neutrals glad we’ve done it, glad to remember how we did it.”

If that’s romance, let’s have more of it.

O’Neill idealistic over Old Firm

It is Martin O’Neill’s brightness of mind as much as his status as a leading manager that makes him a figure capable of exerting appreciable influence in English football. But he is acknowledging no more than an obvious truth in saying that when he advocates the admission of Celtic and Rangers to the Premier League his is probably “a voice in the wilderness”. He is aware, of course, that quite a number of other voices are making similar calls for the revolutionary development but also knows the wilderness of opposition in which they find themselves is vast enough to prevent the most persuasive of them from having practical effect.

There was a sense that O’Neill was being idealistic rather than optimistic when he was quoted last week as arguing that the arrival of the Old Firm would substantially enhance the Premier League and make all the other clubs involved strive to get better. “Glasgow is a phenomenal football city,” he said. “Celtic house 60,000 and Rangers house 50,000. When I was manager of Celtic a number of years ago there was some talk of both teams joining the Premier League. There was mention of them being put in the Championship, or maybe even lower down, then making them work their way up through promotion. They would eventually get to the top and end up as monumental players.”