Real Madrid lead Barcelona by three points heading into this weekend's round of matches and Guardiola admitted that each season was getting more difficult to win the title. "The reality is that we are for the moment behind a team that has been better than us this season," said Guardiola, who last season got the better of their bitter rivals beating them to both the title and in the Champions League semi-finals though losing to them in the Spanish Cup final. "The competition is once again really going to test us. Each year, it becomes more and more difficult to win and this year will be no exception." Guardiola's side may well be six points adrift going into Sunday's Barcelona derby with Espanyol - Real host struggling Granada on Saturday - but the former Barcelona and Spanish international midfielder is not expecting an easy ride from their opponents. "Espanyol is not only a young team, who battle and pressurise other sides, but is also a team that have a good tactical sense," he said. Guardiola also ruled out dipping into the transfer market during the transfer window despite having lost World Cup winning striker David Villa to a long-term injury. "We will not be involved in the transfer window, we are what we are and we will play according to that," he said.