The Belgian youngster proved the matchwinner against Champions League opponents PSV Eindhoven last night.
Motta said this morning to Sportmediaset: "I'm very happy with what he does, both in training and in matches. I know it's not easy for him, sometimes he can make mistakes, it's part of the game. There's a normal reaction, the fans have the freedom to do so, he has to accept it and live with it because it's part of the high level.
"We don't want that to happen, also because he was born in 2004, he needs help. Last year he was in the Next Gen, now he's playing in the Champions League and is helping the team a lot. I'm very satisfied with how he comes in, not only for the goal, but above all for his attitude, which is fantastic: eight for every ball, when he makes a mistake he doesn't stop, he never lowers his head, he's always alert...
"That's what I want to see, I want players like that. He's a young lad, he's growing up quickly. You can't forget the beginning of the season, who was talking about him? Nobody. Today instead we talk about a guy who plays in the Champions League with Juve against a great team like PSV, comes on in the second half, scores, a great performance... He has a fantastic attitude, I'm very happy to have this guy in the group."