“It is the next step. He still has a way to go,” he said.
“He will know that, but when he makes this progress, then he can return in the group for games.
“Of course, we all hope that, because he is a great footballer. He has great skills that can help us.
“We have to cover so many games, but especially we need quality players, and he is definitely a quality player who can make the difference and we are expecting that from him.”
You can see Erik’s full pre-Arsenal Q&A with club media from 07:00 GMT on Sunday morning, on ManUtd.com and in the United App.