Barcelona have been disappointing in the Champions League for two seasons. The only serious problem Xavi is dealing with is this now actually. Because they didn't have much problem on winning the La Liga title. But they just can't deal with big teams in the Champions League properly. This season they had a really terrible group stage experience. I didn't like Lewandowski's performance in big matches here as well. It was like there was a completely different striker than the one who scores so many goals in the La Liga.
Xavi needs to find a way to consolidate the game plan more for next season. Because the board would ask him to do more than this. Maybe tiki-taka isn't the right choice against such teams here anymore so Xavi had better think about a new formula.