The teen jumped from the bench to score the Gunners' third in their 3-0 win.
Arteta said, "What I like is that he comes in, in that context, the first thing he does is take a touch, run forward, run past two players and put it inches away from the post. I understand that, I am responsible for him, and you have to do that brick by brick.
"Today he put in another brick, now we have to put the cement, make sure that it doesn’t get dry, so that he can put in another one and another one and that one is going to stick. Then we put one more layer, we want to put five in a row. Believe me, it won’t work and we have to manage that with his expectations and his load as well, which is really important.
"I think he’s the second-youngest player for the club to score in the Premier League. It’s giving us all the reason and today is another reason to put him there but that’s when I play him and not somebody else. It’s step-by-step, I would say."
On the pressure now on the teen, he added: "Something I cannot do myself, I cannot manage expectations. I will try to educate him, raise him, and give him the pathway that we believe is the best. His family, his agent, his friends, they will be very important as well. Don’t listen too much to the noise, focus on what he does which is to play football and he loves every minute of it and good things will happen to him for sure."