Alain de Royer-Dupre is concerned about the ground being too quick for Beheshtam in Tuesday's Juddmonte Grand Prix de Paris at Longchamp.The Aga Khan's lightly-raced colt is as low as 12-1 for the Prix de l'Arc de Triomphe, despite finishing only fourth in the French Derby. A son of Peintre Celebre, he had won over 13 furlongs on his debut so the drop back in distance for the Prix du Jockey Club counted against him.While De Royer-Dupre is expecting Beheshtam to be better suited by the mile-and-a-half trip, the trainer does not want the ground too fast as he looks to follow up Montmartre's victory in the race 12 months ago."Running over a longer distance will definitely suit him, but we will have to see - he was only fourth in the Derby so it is difficult to know quite how good he is," said De Royer-Dupre."The Derby was only his third run so he is still improving. The ground is going to be good to firm, I think, because we have had no rain in France and it could be a little bit too firm for him. If the ground is too firm we will have to decide whether to run or not when we get there."Everything has gone well since Chantilly, we have had no problems at home with him and he is ready to go. The Arc is possible, but we'll have to wait and see. This will be his fourth race but if he were to go for the Arc, he would need to run in a trial beforehand."