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.
Actually, the current Barcelona squad already has a good mentality for the Champions League competition, but with the style of play given by Xavi, it certainly won't match his opponents in this European competition. Xavi should have been able to learn from his senior who is currently coaching Manchester City, namely Pep Guardiola, who no longer uses the tik taka strategy because this game cannot be used in the modern football era as it is now.
Pep Guardiola always uses tight pressing to find box to box gaps for his players to be able to achieve precise attacks and that is why Manchester City can win the Champions League this season. Xavi must immediately evolve with his players so as not to be left behind by his competitors, especially Real Madrid, who will not be playing anymore to be able to win the Champions League title again.