Nine runners have been declared for the 1m2f contest including the David Simcock-trained I'm A Dreamer. Roger has booked leading US jockey John Velazquez for the ride.
He said: "Nahrain showed at the Curragh last time out that she was coming back to herself and she has excelled at home since.
"Obviously it is a tough race but she looks in great condition and on the best of her form she would have a very good chance."
Last season, Nahrain won the Prix de l'Opera at Longchamp before finishing second in the Breeders' Cup Filly and Mare Turf at Churchill Downs.