Many were surprised when the 19-year-old was starting games from the very beginning of the season.
But the central midfielder had managed to convince his manager that he was ready before the season even began!
"The first impression from him is very good," Emery told the Evening Standard. "We saw this from the first weeks of pre-season when he arrived here and started training.
"For example, his very big decision to decide not to play with the national team in the summer because he wanted to stay and work with us to show his capacity in pre-season. He earned the possibility to take minutes in the first XI.
"His adaptation was very quick. Now his progress is very good. He is very young. We played with Lucas Torreira and Guendouzi as midfielders at Manchester City.
"He is a very young player, his present is very good but his ambition is to grow a lot with us and become an important Premier League player."