The forward played from the start in a 3-1 win over Brentford away from home on New Year’s Day.
While Nwaneri was not at his very best, he did have a productive game in Arteta’s view.
He stated post-game: “Well, in that position it wasn't because of the bug, it was a decision I made because I thought he was the best player to play in the position to start the game and because there was a story there with his debut here.
“He made his Premier League debut and sometimes that feeling comes in and you feel it is the right one and then who knows?”
On Nwaneri's progress, he added: “Part of that development is patience, managing frustration, managing expectation because you expect that everything is going to go so fast as the previous things happens and it's not the case.
“So now we're building him, he's already played a lot of games, a lot of minutes for us, the age that he’s got and he fully deserves that.”