Actors Arjun Rampal and Irrfan, who play RAW agents in Nikhil Advani's forthcoming thriller "D-Day", trained with Hollywood stunt director Tom Struthers for real action sequences in the film. Arjun calls him the "backbone" of the movie.

On the foreign front, Struthers has earlier choreographed action sequences for films like "Dark Knight" series, "Lara Croft" series, "Inception" and "Batman Begins".

"We trained a lot with Struthers. I wish he was here. He has given us some great skills and techniques of fighting, how a RAW agent would fight," Arjun said here Thursday at the first-look launch of the film.

"He (Tom Struthers) is a big backbone of this film," added the 40-year-old.

"D-Day" is a first-hand account of a mission undertaken by Indian secret service agents to capture a most wanted man in India.

In the film, both Arjun and Irrfan have fight sequences, and they were trained for it.

"Irrfan and me had trained very hard in that (real) action because we have a lot of action sequences between us in the movie," said Arjun.

"D-Day", releasing July 19, also features Huma Qureshi, Shruti Haasan and veteran actor Rishi Kapoor.