The former Marseille boss, who takes charge of the African side for the first time in an international friendly against Northern Ireland in Belfast tomorrow, believes the striker has improved considerably since joining the Gunners.

Chamakh, 26, moved to the Emirates Stadium from Bordeaux in the summer and has made a fine start in London, scoring eight times including an impressive double against Wolves last week.

Gerets said: "When he played in France he was very good in the box and scored a lot of goals with his head.

"But I get the impression since he has joined Arsenal he has become a more complete player. They play fantastic one-touch football and he is getting better every week as he gets used to this new kind of play.

"He is doing a great job for Arsenal. It is not easy to change your game but he is doing very well."

Veteran boss Gerets, 56, who first made his name as a defender for Standard Liege, PSV Eindhoven and Belgium has been charged with the task of reviving Morocco, who have under-achieved in international tournaments over the past decade.

"I think there is a big potential," said Gerets, who has also coached Turkish giants Galatasaray and was last in charge of Saudi Arabian club Al Hilal.

"They have a lot of good players. For one reason or another they have not been successful in the last couple of years but I think we can change this."

Gerets has little idea what to expect from Northern Ireland at Windsor Park tomorrow.

Manager Nigel Worthington has made eight changes from the last game, having been hit by a host of withdrawals.

He said: "I heard he will put some young players in - this may not be to our advantage as they will be young, hungry.

"I am looking forward to this game. It will be my first game.

"I have had the team only for two days but my job really starts tomorrow."