The 18-year-old German forward penned a long-term extension at the Emirates Stadium on Monday.
"I think he has a manager (Arsene Wenger) here who will develop him and who has a history of developing young players," the Czech told the club's official website. "Nothing better could happen to him than being offered a new contract here.
"He is a very talented boy; 18 years old and he still has plenty of things to learn and he will find no better place to learn than here. I think it works very well for both sides that he stays here."
Gnabry made his Arsenal debut last season after graduating from the club's youth academy.