#Left-back: Jordi Alba
Barcelona will need Jordi Alba's pace and experience on the left flank to break down opposition defences. Despite being 32, the Spaniard remains a lively presence, and looks solid enough to carry on for the next few seasons.
Alba has been the creative outlet of the team since the departure of Lionel Messi. The defender has bagged five assists for the Blaugrana this season. It would make sense for Xavi to count on Alba, and gradually introduce Alex Balde onto the scene.
#Centre-back: Ronald Araujo
There's no doubt Ronaldo Araujo has been the best centre-back at Barcelona since last season. The Uruguayan continues to impress at the heart of defence, and looks set to continue in the coming years.
At just 22, Araujo has age on his side. The Uruguayan also possesses the talent, personality and leadership to become Barcelona's next defensive general. It's easy to see that he could be a pivotal figure under Xavi.
#Centre-back: Eric Garcia
Eric Garcia and Ronald Araujo have lined up alongside each other at the heart of Barcelona's defence on a few occasions this season. The two players look destined to become Barcelona's first-choice centre-back pairing in the coming years. That could well begin under Xavi this season.
Garcia has made 12 appearances for the Blaugrana across competitions this season. Although the Spaniard hasn't hit top form yet, it is only a matter of time before he hits the ground running at Camp Nou, hopefully under Xavi.
#Right-back: Sergino Dest
Thanks to the sale of Emerson this summer, Sergino Dest has no serious competition for his spot at right-back other than the versatile Oscar Minguez. The USMNT star has the attributes to thrive at Barcelona, and Xavi will likely have to keep him in his starting line-up.
Dest has made 13 appearances for Barcelona across competitions so far this season, recording three assists to his name. It is worth noting that the defender has been one of the top performers for the Blaugrana since the start of the campaign.