Barcelona top Champions League Group H with six points after winning their first two games without conceding a goal. Portugal's Porto are second with three points, ahead of third-placed Shakhtar on goal difference.

In LaLiga, champions Barcelona are third in the standings, trailing leaders Real and second-placed Girona by one point.

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 don't need to take anyone's mind off Saturday's game against Real Madrid because the Champions League makes you focused and switched on... Shakhtar are a dynamic side, strong, and I think they can cause us problems. We can't lose our focus."

Barcelona are also dealing with injuries to several first-team players, including Robert Lewandowski, Sergi Roberto, Jules Kounde, Frenkie De Jong and Pedri.

"I remain optimistic that some of them will make Saturday's game (against Real)," Xavi said.

"Pedri is coming along as we thought. He feels how he feels, that is what you go by as a player day by day. We want to try to avoid a relapse so we have to tread carefully.

"We have a lot of players out but that is not an excuse. The team can compete, play good football and win. The style won't change at all."