Clough has told Sunu to use his pace to hurt opponents but feels the France youth international must improve the quality of his final ball.
"His pace frightens people but he has to learn to use it more. Like most Arsenal players, he wants the ball to feet a lot. That's lovely but he has to recognise that he is very quick, so needs to use that pace. Push the ball past a defender and go," said Clough.
"He did it once against Middlesbrough and went past David Wheater like he wasn't there. The defender brought him down and was booked. So Sunu has to recognise that side to his game but he's 18 and it is all experience for him. He is still learning.
"I think he has improved in each game but there is an awful lot more to come from him. The only thing the other night that was a bit disappointing and frustrating was that there was no end product. He got himself into some great positions and we got him the ball in some great positions but he did not put a cross or a shot in."