#2 Gerard Pique
The Spaniard's importance to Barcelona can be ascertained from the fact that he has started in all but 1 games in both the Champions League and the La Liga. Pique had a tougher season than expected, because his regular partner in the heart of the defense, Samuel Umtiti has missed the majority of the season due to a knee injury.
Pique did not let that affect him or his team. Instead, the Spaniard took Clement Lenglet under his wings and helped the Frenchman settle down, forming a new partnership at the heart of the defense.
This season once more, the Spaniard has provided the defensive backbone for the Catalans. His composed stature and assuring presence at the back has helped Barcelona play their normal attacking game. But the Spaniard has not just held the fort at the back, he has gone forward on every occasion and has been a threat from set pieces too.
Pique has already scored seven goals and has registered two assists so far this season. He has been one of the best defenders in the world so far and is also a contender for the Barcelona player of the year award.