Barcelona defender Marc Bartra has no doubts that his side are capable of winning the Champions League this season.

The La Liga champions opened their new European campaign with a 4-0 win over Ajax at Camp Nou in Group H on Wednesday, thanks to a Lionel Messi hat-trick and a Gerard Pique header.

"The tempo of our play was very high tonight," Bartra told reporters. "That is what the Champions League requires. All our opponents come at us hard, they have clear game plans and the intensity of all these matches is really high.

"You can never drop your guard, not for a moment. Our team is really focused, we know what is needed. We fought for, and won control of the game and we come away from this Ajax test pretty content with how it went.

"Today we showed greater defensive intensity. Messi is the best footballer in the world but he is also the first to take responsibility for pressing and starting our attacks with hard work."

Barca travel to Rayo Vallecano in La Liga on Saturday.