"'Gunday' director ('Ali Abbas Zafar') comes to my gym regularly and he was my junior in college, so he must have seen me in the gym. My look and body impressed him and he felt that only I can fit the role that he has in his film," the 40-year-old said in an interview.
"It is a cameo but since he is from my college and a good boy so I went up to him, heard about the role. I found it interesting, besides, people have not seen me in such a look and it is a Yash Raj film and the co-actors are also good. So, I said yes," he added.
"Gunday" features Ranveer Singh and Arjun Kapoor in lead roles, along with Priyanka Chopra and Irrfan.
Sushant also said "Hate Story 2" will go on floors in Jan next year.
"Vikram Bhatt is producing 'Hate Story 2' and I am doing that. Surveen Chawla is there. Vishal (Pandya) is directing it and it will start in January," said the actor.
Sushant, who became famous as the dacoit in Ram Gopal Varma's "Jungle", will soon be seen in "Four Two Ka One".