Hertha Berlin boss Pal Dardai is heavily critical of Arsenal midfielder Matteo Guendouzi.
Dardai has admitted that Guendouzi is still a long way off from the level required to reach the very top while claiming he has a rebellious instinct.
Dardai told Bild: "It's like puberty for him, he's kind of a rebel. He has to work and learn like an animal."
On the weekend, Guendouzi came in for criticism after going down inside his own penalty area far too easily just seconds before RB Leipzig scored - moments after coming onto the pitch.
And Dardai admitted that he needs to cut that behaviour out of his game as quickly as possible.
He added: "In training, I always stop these kind of duels because you can't fall to the ground like this. And, afterwards, he's mad."