A 4-2 defeat on Sunday at home to Girona, who went top, saw the defending league champions slip to fourth in the standings, seven points behind the surprise leaders, and Xavi explained what he meant when he said they were under construction.

"We're under construction because we've been in the Europa League for two years. I'm talking about this construction," Xavi told a press conference ahead of their game with Royal Antwerp.

"But in that same construction, what you have to do is win. Which is what we're doing, a league and a Super Cup. Otherwise, I wouldn't be here.

"I mean the team has to be much more consistent. When I say we're under construction, I don't mean that it takes time, but the team's play. I think we're halfway to making Barca great."

After Sunday's defeat, the manager expects a reaction from his players when they travel to face Antwerp on Wednesday.

"Behind closed doors I see that they are angry because we were better than Girona and we deserved to win but we didn't manage it," Xavi said.

"The dressing room is angry and eager to react."

The game in Belgium does give the manager a chance to rotate his side.

"At this stage, already qualified, it's a good time to give opportunities to younger players who have played fewer minutes," the manager said.

"The normal and logical thing is that we make changes tomorrow. The idea is to make changes and rest players who have fatigue and accumulate a lot of minutes... but tomorrow we'll decide."

Barcelona have 12 points in Group H, making the knockout stages for the first time in three seasons. Porto and Shakhtar Donetsk are both three points behind and if Barcelona lose and Shakhtar win, top spot will be decided on goal difference.

Antwerp are bottom with no points.