Oct 24 (Reuters) - Barcelona cannot use their injury crisis and their upcoming league game against Real Madrid as excuses for a poor performance in a midweek Champions League clash against Shakhtar Donetsk, coach Xavi Hernandez warned on Tuesday. Barcelona top Champions League Group H with six points after winning their first two games without conceding a goal. Despite their more comfortable position in their Champions League group, Xavi said Wednesday's home clash with Shakhtar was vital, telling reporters: "The three points tomorrow against Shakhtar are key for our objective. "This is the Champions League, the biggest competition there is for clubs and for us getting nine points from nine is very important. "I remain optimistic that some of them will make Saturday's game (against Real)," Xavi said.

---

Persons: Xavi Hernandez, Portugal's Porto, Xavi, Robert Lewandowski, Sergi Roberto, Jules Kounde, Frenkie De Jong, Aadi Nair, Clare Fallon Organizations: Real Madrid, League, Shakhtar Donetsk, Barcelona, Champions League Group, Shakhtar, Real, Champions League, Thomson Locations: Barcelona, LaLiga, Girona, Bengaluru