Marc Bartra has warned Barcelona's domestic and European rivals that losing Pedro does not make the Catalans any less "unstoppable".

The treble-winning Blaugrana begin the defence of their Liga title on Sunday without the 28-year-old - and legendary midfielder Xavi, who joined Al Sadd in June - after he joined Chelsea in a £21.4m deal this week.

Pedro had struggled for regular games last term as the formidable trident of Lionel Messi, Luis Suarez and Neymar helped Barcelona to a clean sweep of honours.

"Losing Xavi and Pedro hasn't made us weaker," the Barca defender told the club's official website. "I'm going to miss them a lot but teams like Barça lose very good players and get back very good players.

"We still have a good group of homegrown players. You can't always bring up players who are ready for the first team.

"But with those who have joined us from other clubs, we'll continue to be unstoppable."

Pedro started 21 games in all competitions last term.

Luis Enrique's men travel to San Mames this weekend to open their 2015-16 campaign by facing Athletic Bilbao, who pipped them to Spanish Super Cup glory earlier this week.