Barcelona forward Lionel Messi has backed old nemesis Jose Mourinho to make a successful return to Chelsea but insists Real Madrid will not be weakened by the departure of the 'Special One'.Messi is under pressure to deliver for Argentina, having never really reproduced his club form at international level, and realises next year's World Cup in Brazil is a real opportunity to finally win a trophy for the Albicelestes. "If God wills it, then we will win the World Cup," he added. "We still have a year to go until the next tournament and we need to keep developing and improving. "We still have some way to go but I think we have time. We need to keep improving and it would be a dream for us to win the World Cup."