Villa splashed out £30m to land Guessand from Nice.
Ahead of today's clash with Arsenal, Emery said: "He needs time, and he's competing very well.
“I'm so, so happy with him, and especially because we are trying to get in our structure his best position to help us and support us in our structure with his qualities.
“He's working hard to adapt quick, to get tactically everything we need, and he had one chances to score with the head on Wednesday.
"He has worked defensively very well. I am now, and I was happy. Now I am happy. I am demanding with him, but firstly, he must be demanding himself, and he's in this commitment.”
On Guessand's best position, Emery added: "In the attacking third, he can play right, he can play even as a striker and he can play on the left side.
“We decided to play as a right winger and try to get there the the tactical objective we have collectively and then individually, using him with his skills.”