The young midfielder is enjoying a breakthrough season, recently scoring in back-to-back games, including in the 5-1 win over Manchester City.
Despite his rising status, regulations prevent him from fully integrating with the senior squad until he turns 18.
Manager Mikel Arteta said: "Ethan cannot be in our dressing room still, which is unbelievable.
"He needs to get dressed somewhere else, even on match day."
Arteta continued: "When you see those two (Miles Lewis-Skelly and Nwaneri) walking next to each other, talking to each other, there is a bond there and a chemistry there.
"I imagine for them it is special because at the moment they are still in different dressing rooms.
"So to have somebody close to him that has that trust, that confidence, that link, I think it is lucky.
"They are very lucky to have each other."