The Champions League had been a tonic for Arsenal. They suffered at the hands of Chelsea on the domestic scene, but Arsène Wenger's team have outlasted them in European competition. Now the therapeutic effect of success over continental rivals is at high risk of coming to an end. Fatalism is pointless, however, and the encounter with the holders Barcelona should inspire Arsenal, who would love to emulate these opponents as well as beat them.
Wenger and his opposite number Pep Guardiola have a shared vision, even if the Catalan has the greater means. The Barcelona coach, indeed, has that edge over just about everyone else since there are few players to compare with Lionel Messi. Arsenal, all the same, possess a collective menace and have outscored every other club in the Premier League in this campaign. Their meeting with Barcelona is the most enticing of the quarter-finals.
Manchester United's appointment with Bayern Munich does not have quite such lustre. The fixture will always stir memories of the 1999 final, but Sir Alex Ferguson's squad was knocked out of the Champions League by the Bundesliga side two years later. There is nothing about this season's reunion to make the pulse race, although it would be wise to take care against any team under the command of Louis van Gaal.
Arsenal, of course, have history against Barcelona in this tournament. Despite having their goalkeeper Jens Lehmann sent off early in the 2006 final they took the lead through Sol Campbell's header and were not overhauled until late in the match when the substitute Henrik Larsson set up two goals. Of the men who started in Wenger's line-up that night only Campbell, Emmanuel Eboué and Cesc Fábregas continue to be on Arsenal's books.
Barcelona's rebuilding has been almost as thorough and the obvious connection with that evening in Paris is Thierry Henry, who switched from the Emirates to Camp Nou three years ago. At 32, he may not be so great a factor in the quarter-finals. It may even be a sentimental mistake to take it for granted that firepower will be decisive. As it happens, Barcelona have been outgunned by Real Madrid so far in La Liga and show signs of fatigue after triumphs in domestic football, the Champions League and, for some players, Euro 2008.
It can be argued that well-drilled resilience has become critical. The contrast between the quarter-finalists is most marked in the defensive records. Barcelona have conceded 16 goals in La Liga to date, while Arsenal have shipped 33 in the Premier League. This is not simply a matter of Guardiola's line-up holding possession for so long that opponents, exhausted by all the chasing, start to feel the ball has been confiscated permanently.
Barcelona also defend well and, whether picking Sergio Busquets or Yaya Touré, have a holding midfielder of a calibre still lacking at the Emirates. All the same, there is a persistence to Arsenal that merits praise. Another side might have become prey to introspection and depression following the 3-0 loss at home to Chelsea in November, but the players regrouped and demonstrated consistency in the routine fixtures which, after all, offer the same three-point reward.
There still does not appear to be any compelling reason to suppose that Arsenal will get the better of Barcelona. Whichever of them prevails faces a gruelling examination in the semi-finals by, most probably, Internazionale, assuming that José Mourinho's side can deal with CSKA Moscow. The other half of the draw does not appear quite so gruelling.
Bayern are still under development and their affluence sometimes makes little impression, particularly in the group stage this season when they lagged six points behind Bordeaux. Van Gaal's team squeezed into the quarter-finals after beating Fiorentina on the away-goals rule. The feeling that Bayern underachieved was embodied by the coach's complaint that one of the opposition's goals would have been prevented if Franck Ribéry had carried out his marking duties.
The winger, as Van Gaal emphasised, did make an impact when taking the game to Fiorentina. With Arjen Robben also at work, Bayern can expect to have exciting spells and they head the Bundesliga at the moment. United still seem more settled and have been methodical. It should be of benefit to Sir Alex Ferguson that the second leg is at Old Trafford. His squad might look in need of renewal but, in the immediate future, its settled nature should be a virtue.
Were United so presumptuous as to cast an eye over the semi-final prospects, they might envisage an intriguing occasion. Bordeaux, who had troubled moments against Olympiakos this week, lead Ligue 1. Lyon, who are also in contention domestically, have their thoughts fixed on the Champions League, where they knocked out Real Madrid in the last 16. Claude Puel's squad had previously won at Anfield in a group fixture.
The English presence is once again marked, but the challenge is growing steeper.
