Barcelona fullback Jordi Alba admits they weren't at their best for the 4-1 defeat of Alaves.

The Blaugrana are top of LaLiga Santander and have qualified for the last 16 of the Champions League, but they have yet to impress on the pitch this season.

"We feel good, but we must improve a lot to win all the trophies," Alba said.

"[For 2020,] I ask to win all the trophies, like every year."

Whistles were heard from a part of the Camp Nou crowd on Saturday afternoon as the Catalans struggled to put the game to bed, with Alaves having cut Barcelona's lead to one goal.

"The whistles are understandable," Alba added.

"When things don't go to plan it's normal, but then we controlled the game.

"We had some doubts, but we finished feeling very happy with the victory."