FC Barcelona head coach Xavi Hernandez stated a belief that his team’s slump in form is down to “more of a mental issue” than a “physical or game issue” following their shock 1-0 defeat to Shakhtar Donetsk in the Champions League on Tuesday.

In one of the elite European competition’s early kick offs, Barca was unable to respond to a first half header from the Ukrainians’ striker Danylo Sikan with a quadruple substitution Xavi made around the hour mark failing to have a positive impact.

Post-match, Xavi had to admit as he did on Saturday at Real Sociedad that his men “didn’t play a good game”.

“Nothing has gone as planned. We wanted to guarantee qualification [for the next round], but it’s a very clear step backwards. The Champions League demands the highest level but we haven’t found it. We’re angry. We couldn’t fail and we have failed. It’s a big mistake on our part,” Xavi said, in comments carried by Mundo Deportivo.

Whereas at the weekend Xavi blasted his team for their lack of intensity in the 1-0 win sealed by a Ronald Araujo injury time header, he didn’t agree that this was the reason for another poor display in Hamburg which he instead put down to “bad play”.

“We didn’t understand what the game required. We didn’t attack well. We didn’t defend that cross well [for Sikan’s goal] and mistakes cost us dearly.

“There was attitude and intensity in the second half but we didn’t manage to do it. The reaction [to falling behind] was good but insufficient,” added Xavi, who thinks that “the small details are taking their toll on” Barca.

“We are at a low point in terms of play and turnovers, and how to attack. It can happen. Nothing is lost. We’ve played one of the worst games tactically in these two years [Xavi has been in charge]. It was an inopportune time. We must be self-critical,” Xavi demanded.

“We are at a low level of confidence and we have to reset. We didn’t feel comfortable in the game. It’s a bad feeling we have in the dressing room and also me as a coach.”

With three points separating the top three teams ahead of the Portuguese meeting Royal Antwerp, a match at the Montjuic Stadium between Barca and Porto later this month is now a must win for the Catalans that could decide who wins Group H.

Xavi pointed out how Barca’s fate still lies in its own hands and that they can mathematically achieve qualification to the next round by beating Porto.

Above all, however, he wants his side to show “pride” and “character” which they must find once again.

“Not long ago we played very good football and that happens during the season … It’s more of a mental issue rather than a physical or game issue,” he stressed.

“We are doing things wrong in general, both in attack and defence. We are conceding too much,” said Xavi.

“It’s taking its toll like it did against [Real] Madrid and again today. We have to generate more positive things.

“It’s my job as a coach and the players to take a step forward. It’s up to me to regain dynamism and confidence. The players have a high level and they can do much better than what they are doing. Nothing is lost but we are in a bit of a football slump.”

Refusing to be drawn into passing comment on decisions that didn’t go his way, Xavi said that he wasn’t thinking about such things and instead focusing on getting the team back to being itself.

On being “recognisable again, enjoying ourselves and feeling comfortable”, to be more specific.

In their last match before the international break, Barca hosts 14th-placed Alaves in La Liga on Sunday with a comfortable win capable of boosting confidence and morale.