Barca is in a rotation of players in their defense. they had been strong at the start of the season. but to play consistently, of course, it is impossible for players in the Barca main squad with so many matches.
Barca now has a weakness, and Xavi will of course have to take this into account for the winter transfer window. looking for a formidable defender to become a strong fortress of Barca.
The mainstay players from Barcelona are not able to play consistently because it requires very high energy to guard at the back which is very vulnerable to opponent attacks, Many defenders are injured because of the previous game, therefore Xavi must carefully consider the formation for each game so that get good results.
Barcelona have many quality players, but some of them are often injured.
Xavi had to find a way to keep Barcelona's players fit. Moreover, the availability of players becomes very important in the midst of an increasingly crowded schedule. The problem of defense should be the main focus to be improved, although it has brought in a number of players in this sector, but they do not look cohesive at all.
I saw the different performances that Barcelona had in La Liga and the Champions League. Barcelona looks so solid when playing in La Liga, they only lost once when they were defeated by Real Madrid at the Santiago Bernabeu. While in the Champions League Barcelona looked less consistent, defeats were so easy to come by which made it difficult for them to penetrate the round of 16.
Injuries are unavoidable, some of Barcelona main players had suffered injuries before an important match. Xavi should not be too dependent on certain players, he must rely on several back-up players to be the ideal substitute when the main player is injured.