In an interview, director Shankar revealed that he approached Amitabh Bachchan to play the villain in Robot. By that time, Rajinikanth and Aishwarya Rai had been signed to play the lead roles.
According to Shankar, Big B liked the script, but had reservations about playing villain. The director wanted Rajini and Big B to face each other and reportedly ready for some changes in the script. But a firm no from Big B paved the way for Danny to play the baddie.