The Vishal Bhardwaj-directed movie brings together the two stars for the first time on screen.
The movie started making headlines since it was announced, due to the 'personal' history the two actors share.
"Rangoon" also stars Kangana Ranaut.
"I have shot for one, one-and-a-half days with him. He (Saif) is very professional, nobody could have done the role like him. He is a great cast in the film, same goes to Kangana, who has been doing great work. Looking forward to know how people will react to the casting," Shahid told reporters at the 11th Guild Awards.
The 34-year-old actor's solo release this year, "Shaandaar", failed at the box-office. Shahid said a film's failure is as bad as a break up.
"It hurts when a film doesn't work. You put in so much of hard work and if it doesn't work then you experience pain, anger. You go through the same emotion you go through a breakup," he said.
The "Haider" star tied the knot in July this year to Delhi girl Mira.
Praising his wife, the actor said, "She's independent. Her opinion is very important to me."