Barcelona coach Ronald Koeman has told Frenkie de Jong he must do better.
Koeman has been left disappointed by De Jong's form in preseason and has told him he was expecting more.
AS says Koeman is going to be "relentless" in his approach to his fellow Dutchman, convinced he has been playing within himself since joining from Ajax a year ago.
De Jong impressed for Holland with Koeman in charge and the latter now wants more of the same in a Barca shirt.
Koeman wants Barca's game to be played through De Jong, but the 21 year-old needs to improve on his error-ridden performances so far in preseason.
