Well I will prefer him centrally if the team had a reliable leftback(Defensively),he adds pace and his passing in the build up is superb,he also can cover the space behind the leftback as he is good in reading the game and he can use his pace in covering which may allow the team to use an attacking minded left back wihout needing another defensive midfielder or Keita in covering him,despite all of this He cant feature in the best XI for Barca as Maxwell and Adiano are both good but terribly inconsistent
so for now his best position is as a leftback considering the fact that there are 2 world class CBs in the team plus a LB in the Barca system actually end up as a 3rd centreback