Barcelona coach Pep Guardiola believes his side needs to keep improving despite their excellent form at the beginning of the new season.

Barca thrashed Atletico Madrid 5-2 at the Nou Camp on Saturday night with another thrilling display of attacking football.

But Guardiola says his team were merely efficient in that match and sees room for improvement ahead of Tuesday night's trip to Racing Santander.

"We still can and must do a lot better,'' he said.

"On Saturday I think we had seven or eight shots on goal and they had 5 or 6 dangerous opportunities; we were efficient, but we didn't have control.''

Barcelona have won all of their three league matches so far this term and are behind leaders Real Madrid on goal difference alone ahead of Tuesday's game at Racing.

Guardiola believes the match at El Sardinero represents a big test for his side.