The winger was rewarded by new Head Coach Tim Sherwood for his fine cameo off the bench in the win at Southampton with a start against West Brom on Boxing Day.
Nacer had three shots at goal, three successful tackles and an 81 per cent passing accuracy in a 75-minute stint as it ended 1-1 against a stubborn Baggies side at the Lane.
That was Nacer's 10th appearance and seventh start in the Premier League and Mousa, his Belgian international team-mate, expects more to come.
"I know Nacer very well and I know he is an unbelievable player," he said.
"I think he's done well. He hasn't played that much yet but I know when he does everyone will be even more surprised with what he can do."