Ernesto Valverde has no problem with his Barcelona side being whistled by the fans at Camp Nou, the coach calling on the players to respond after they were held to a 0-0 Champions League draw by Slavia Prague.

Barca failed to get back to winning ways following their 3-1 LaLiga defeat to Levante at the weekend, piling the pressure on Valverde.

Lionel Messi hit the crossbar and he and his team-mates were frequently frustrated by Slavia goalkeeper Ondrej Kolar, who produced an inspired display in between the posts.

Slavia were excellent value for their point, however, with the result leaving Barca still with work to do to progress from Group F.

Speaking afterwards to Movistar, Valverde said: "The other day we lost against Levante and it does not escape us that the last two have not been our best matches.

"We know there is a lot of pressure on the team and we have to respond."

Asked about the whistles, he added: "It is okay to be demanding of the team."

Jordi Alba was replaced at half-time because of a hamstring injury and Valverde said the full-back will have tests to reveal the extent of the issue.

Alba's potential absence is another blow to a Barca defence that will be without Gerard Pique in their next Champions League meeting with Borussia Dortmund on November 27 after receiving his third booking in this European campaign.