Barcelona head coach Xavi was keen to remind his players that Sunday's trip to Atletico Madrid "won't decide anything" as he looked to ease the pressure on the league leaders.

Barca headed into matchday 16 at LaLiga's summit thanks to having a better goal difference than Real Madrid.

But with Los Blancos in action on Saturday, Barca could begin the game trailing Carlo Ancelotti's men in the table.

It promises to be one of Barca's toughest fixtures of the season and comes amid an underwhelming return to action following the World Cup, with the Blaugrana held to a 1-1 draw at home to Espanyol last Saturday before needing extra time to beat third-tier opponents Intercity 4-3 in the Copa del Rey on Wednesday.

Nevertheless, Xavi did not want to overstate the importance of Sunday's game, even if he tempered his tranquillity by highlighting Barca's habit of shooting themselves in the foot with individual errors.

"Every week is like this: the next game is the most important. It won't decide anything, but [dropping points] would be a blow on the table," he told reporters.

"It's a complicated place to go and they are a rock defensively. It will be difficult for us to generate things and we have to be more effective than in the last few two games, [but] it's not a transcendental game for the future of LaLiga."

Regarding their mistakes, he added: "It's more of a mental issue than a game issue.

"We've dominated and created chances, but we have to kill the matches. We have to be more forceful in certain areas. We're far superior to our rivals but we make occasional mistakes.

"In the end we all fail. We try to give the players confidence so they don't make mistakes, but football is a game of mistakes.

"We have to minimise those mistakes to win. Against Intercity we made life difficult for ourselves."

Although Barca are doing well in LaLiga this season, they have already been knocked out of the Champions League and have the difficult challenge of Manchester United in their Europa League play-off.

It is in such competitions – and the Copa del Rey – where Xavi feels Barcelona's lack of decisiveness is proving problematic, rather than LaLiga.

"Against Espanyol we lacked aggressiveness in the opposition's area and we lacked effectiveness. Against Intercity it was different. We conceded three goals and this can't happen. We have to be more aggressive.

"In LaLiga we are very plugged in, but in other competitions it is costing us more. In the knockout competitions, one detail can knock you out."

It was put to Xavi that Barca lack obvious leaders, particularly following the retirement of Gerard Pique.

But this was not a suggestion he agreed with.

"We have [leaders]," he continued. "Sometimes it's not necessary to raise your voice.

"[Andres] Iniesta did not raise his voice… There is always someone who expresses things with their voice, and others express with personality. We have several profiles.

"There is no problem of personality or leadership. Everyone knows their role in the squad and that's not the problem."