Barcelona's preparations for the new LaLiga season ended with a disappointing 3-0 defeat at home to Monaco in the Joan Gamper Trophy at the Olympic Stadium on Monday.

Lamine Camara, Breel Embolo and Christian Mawissa struck in the second half as the Ligue 1 side became the first team to beat Barça in their annual curtain-raiser since Sampdoria in 2012.

The loss rounds off a mixed preseason for Barça under new coach Hansi Flick after wins against Manchester City and Real Madrid were followed by a defeat to AC Milan in the United States.

This summer's international tournaments and injuries have prevented Flick from fielding his strongest side so far, with Ronald Araújo, Pedri, Gavi and Frenkie de Jong among those still sidelined with fitness issues.

Ferran Torres and Lamine Yamal did feature for the first time in preseason against Monaco, coming off the bench in the second half, but Ilkay Gündogan was forced off with an injury.

Barça kick off the new LaLiga season on Saturday with a difficult trip to Valencia.

Monaco, meanwhile, will begin the new Ligue 1 campaign with confidence at home to Saint-Étienne this weekend after a resounding win against the Catalan side.

Barça had the better of a quiet first half with striker Pau Victor, who scored a brace against Madrid last week, missing the best chance.

Raphinha had a goal disallowed for offside after the break before Monaco struck twice in seven minutes to silence the crowd of just over 40,000 in Montjuic.

Camara netted the first in the 50th minute after young midfielder Marc Bernal was caught out for Barça, with Embolo scoring the second seven minutes later with a dinked finish inside the box.

Yamal was introduced to a warm reception from the home fans after his exploits with Spain helped them win the European Championships this summer and he immediately set up a chance for Victor, who lifted his finish wide.

Barça then lost Gundogan to a head injury before Mawissa struck late on to seal the Blaugrana's biggest ever defeat in the Joan Gamper Trophy.