Barcelona coach Xavi Hernandez has praised striker Robert Lewandowski for helping to change the mindset at the club.
The Catalans are eight points clear of rivals Real Madrid at the top of La Liga and beat Los Blancos in Saudi Arabia to win the Spanish Super Cup in January.
Last season, Barcelona failed to win a trophy but the mood changed in the summer when the club brought in a number of players, including former Bayern Munich striker Lewandowski.
“Lewandowski is used to winning titles with Bayern. He has brought us a winning mentality, a championship,” Xavi told reporters on Friday.
“In his head, defeat is not an option.”
The 34-year-old Poland international has scored 23 goals in 26 games this season for Barca.
Barcelona can overtake Madrid if they win at Villarreal on Sunday, before Carlo Ancelotti’s side face Elche in midweek, due to their participation in the Club World Cup.
“Every game is key and more so at this stage of the season,” added Xavi.
“We are eight points ahead, tomorrow we can make it 11.”