Until March of 2017, Barcelona's season has been awfully inconsistent for one simple reason: the lack of a really talented right-back. Sergi Roberto was made the starting player in that position, but failed to replace Dani Alves in an effective way.
It wasn't until Luis Enrique changed to a 3-3-1-3 formation with Roberto alternating between center midfield and right wing that the Blaugrana overcame their full-back troubles and went back to dominating opponents and winning big matches. But there's still the need of a good right-back next season, and Barça have a clear target.