From his scout report -
"With regards to Aaron Martín’s style of play, time will tell whether or not the left back will make use of his strong dribbling skills and alter into more of a wing-back than the current left full back position that he has adopted at present. As a player that seems confident in possession of the ball as well as a left-back that is not afraid of crossing and playing the ball off the ground it would seem only natural that Martín may follow the modern-day trend of becoming an inverted wing back but in terms of his qualities at left-back, he shows every sign of following in the footsteps of Juan Bernat, Jose Gaya and Jordi Alba and becoming the next in an ever-growing list of exceptional left backs that Spain have produced in the last decade."