The film was dubbed as a "Rajinikanth-starrer" when it was first announced, adding that Rajinikanth would feature in three different roles in the film. Before the film's official announcement, Trisha Krishnan was reported to be signed up for a lead role,[11] but was eventually false. Later reports stated that Anushka Shetty, Deepika Padukone, Asin, and Sneha were approached for lead roles.[15][16][17] The role eventually went to Padukone who signed up in February 2011.[18] Sonu Sood was signed to play the film's antagonist.[19] Later that month, Madhuri Dixit was linked to the project, whom media reports claimed was offered a supporting role, which she later refused citing personal commitments and differences with the role she was offered.[20] Several media reports subsequently emerged, stating that Bollywood actresses Rekha and Vidya Balan were slated to be part of the leading cast.[21][22] The following month, however, it was reported that Rekha walked out of the project during its pre-production stage after a dispute with the producers about her salary.[23] Balan was also reported to have dropped out of the film after an untimely request to fully view the film's script was turned down. In the meantime, Amitabh Bachchan and Hema Malini were reported to have been signed up for important roles, marking the former's Tamil cinema debut.[24] All reports, however, were finally downplayed by K. S. Ravikumar, stating that no other actor had been signed up, other than Rajinikanth and Padukone, as of March 2011.[25] Ganja Karuppu was signed up the following month as the film's comedian, after the possibility of Vadivelu was turned down due to his controversial motifs during the 2011 legislative assembly elections in Tamil Nadu.[26]
R. Rathnavelu was specially chosen by Rajinikanth as the film's cinematographer,[27] after the two worked together in their prior successful venture Enthiran (2010).[28] Rajeevan was signed up as art director.[28] Anthony and A. R. Rahman, who were also part of the Enthiran team, were signed up as the film's editor and composer, respectively.[29] S. Ramakrishnan was signed up as the film's dialogue writer.[30]
