The Argentine has made it clear that Barca will have to improve if they are to get a good result against Athletic BilbaoBarcelona coach Gerardo Martino has admitted that Tuesday's Champions League loss against Ajax worries him as the Catalans prepare for this weekend's Liga game versus Athletic Bilbao.
The Blaugrana's unbeaten start to the 2013-14 campaign came to an end at the Amsterdam ArenA this week and Martino has stressed that they will have to do better in Bilbao on Sunday if they are to get a good result.
"We have talked about the game against Ajax and what's happened worries us. We cannot forget what we did wrong, just like we should not forget the good things," Martino stated at a press conference.
"We've analysed our performance and we all agree that we have to show a different face versus Athletic.
"Obviously, I would take it right away if we could win 20 games and then lose one, but we have to make sure the game against Ajax was an incident and not the start of a bad series.
"Our main goal now is to do well in the remaining games this year. We want to win our Champions League group and hold on to our lead in La Liga."
Barcelona will still be without the injured Dani Alves, Jordi Alba and Lionel Messi against Athletic, while Carles Puyol has also been ruled out due to a knee injury.