Barcelona Faces a Challenge, but It's Not Impossible LONDON - Possession in soccer is not even one-tenth of the law, and goals are the only statistics that count in winning or losing matches. Right now, Barcelona is the best team in the world, and it has the titles to show for its marvelously appealing style of play. But in the span of just four days starting this Saturday, Barça could lose both the Spanish league and the Champions League trophies it now holds. Lionel Messi and company are down in both competitions. They lag four points behind Real Madrid in La Liga, and they trail Chelsea by a goal after losing the first leg of its Champions League semifinal, 1-0, in London on Wednesday night. If there is to be salvation, it will come at the Camp Nou, where Barcelona hosts Madrid on Saturday and Chelsea on Tuesday. Barça has one big advantage, and two handicaps. The advantage is the stadium itself - where 99,000 Catalan fans can lift their team, and where the field is vast. The handicap is that Barcelona relies on a small group of mobile players. They perform more often than others because as the holder of national, European and world titles, Barça goes farther and has to play longer in competitions than any rival - much like a Grand Slam winner has to do in tennis. Weariness is a problem, and so is injury and illness. Barcelona's defense is lacking Gerard Piqué and Éric Abidal, its attack has missed David Villa for months, and the playmaker Xavi Hernández seldom performs free of muscular fatigue. Excuses, however, also count for nothing. As the rain fell remorselessly on Stamford Bridge stadium Wednesday, Barcelona created two-thirds of the attacking plays, and it missed five clear chances to score. Correction: Two of those opportunities were denied by thrillingly athletic goal-line clearances by Chelsea defender Ashley Cole. Two more, from Alexis Sánchez and Pedro, struck the frame of the goal. And not one chance fell to Messi. He was driven deeper, setting up others, but was often hounded by four Chelsea players at any one time. For the most part the Blues squeezed out the genius of Messi, and wrung him dry by the perfectly legitimate method of attaching clusters of defenders to his every move. Indeed it was a moment, a very rare moment, of Messi inattentiveness that led to the breakaway goal. Frank Lampard robbed the Argentine of the ball, like a pickpocket relieving an unsuspecting traveler of his wallet. Lampard released Ramires down the left with a pass from just inside the Barcelona half of the field. Ramires then picked out Didier Drogba, who was lurking just yards from the goal. The surprise was that Drogba was on his feet. The big Ivorian, possibly playing his last Champions League match in London, had spent much of the evening throwing himself to the turf claiming injury and foul play where, mostly, none existed. But the 34-year-old actor still remains active enough when he sniffs the scent of a goal. He promptly fired, left-footed, a shot that was too powerful for Victor Valdés to save. That was it: the game winner on the stroke of halftime, coming from Chelsea's only shot on target the whole night long. "Goals win games" is among the oldest clichés in the sport. The statistics told us that Barcelona commanded 72 percent of possession and completed 782 passes to Chelsea's 194. "We had more possession, but that doesn't mean a thing," said Barça's coach, Pep Guardiola. Congratulations to Chelsea. When we passed halfway, they were waiting for us, defending deeply and in number. They outjumped us and were physically stronger. My players were disappointed, but I know them: They will give absolutely everything they have to reach the final. That will be everything they have left after they play Real Madrid for 90 minutes on Saturday. The common factor is that the tactics used by Chelsea were engrained into the London team by its former coach, José Mourinho, and he will be directing Madrid against Barcelona just three nights before Chelsea arrives at the Camp Nou. Mourinho learned much of what he knows about Barça when he was an assistant there in the late "90s, when Guardiola was still playing there. He has shown since, as head coach with Chelsea and Inter Milan and Madrid, that he will stop at nothing to prevent Barcelona's moves from flowing. The Madrid players that Mourinho currently advises should be better than having to resort to brawling. Some of them are teammates with the Barcelona players on the Spanish national team, and they won the 2010 World Cup together. And there were signs the last time the two giant Spanish clubs met that the men in white had rebelled against some of the extreme negativity demanded by their coach. One hopes so, because Real is atop of La Liga on merit, and because great players, as most of them are, should go to a place like the Camp Nou intent on trying to win the games based on their skills, not through foul play. El Clásico is normally the outstanding contest of the season. Now it is sandwiched between the semifinal legs of a Champions League tournament that could take both Barcelona and Madrid to the final - or neither of them. The key to Saturday, and Tuesday, is whether Barcelona has the resources, the reserves of stamina and confidence, to emerge twice in four days against redoubtable and highly motivated opponents. "Our challenge now is to reverse the result," concluded Guardiola. And it is a challenge we accept. The challenge for the opposition, on both sides, is not to be beaten in the Catalan cauldron. Madrid and Chelsea have only to tie their games to dethrone Barcelona in different tournaments. But the field is huge in Barcelona and there is more space to defend, and that makes it very tough for a team to hide against a Catalan squad that will now attack with even greater persistence.