Nico says he has accelerated his development thanks to working with manager Pep Guardiola and teammate Rodri.
"It’s really nice but it’s hard. You have to improve, he wants the best from everyone. That’s why he is the best,” he said of Guardiola ahead of Tuesday’s Champions League clash with Villarreal.
“That’s been good for me. I have improved a lot. And that’s why I play football, to be the best I can and I think I am doing a good job.
“He is really intense and he tries to show you what you have to do better. But then after he explains everything, you keep thinking about everything and how you can improve. And even now I still think about them when I go to the pitch.
“What he asks, I was asked before. I played at Barcelona and it is similar. But there are details and you are looking for improvement.
“The main idea, I think I already understood before coming here and that helped me to get used to playing here.”
Asked to detail what Guardiola wants from him, Nico said: “Many things. For example, when to move.
“As a midfielder you have to run a lot but do it in the right moment. That is what I have been working on with him. That’s maybe the most important thing.
“When I talk to him, he says I can keep the ball and play but the moment I move it is important too.”
And on advice from Rodri, Nico added: “Every game.
“The last game at half-time he gave me advice about what he saw. He knows a lot about what I should do in that position.
“He is one of the captains and that is a really important role. He tries to guide us, especially the young players.
“He tries to help us understand better the way we want to play.”