Barcelona midfielder Frenkie de Jong admits they weren't at their best for victory over Celta Vigo.
However, De Jong says a win was crucial going into their clash with Real Madrid.
He said, "It was very important to win to be leaders before the El Clasico.
"We didn't think about Inter before Celta, so now we only think about Wednesday's game.
“Today we suffered, especially in the second half. You have to win these games to fight for the LaLiga.
"We have to improve a lot in the game."