Apoorva just cannot make a film without one of the Bachchan's being in it. So Abhishek Bachchan, a dear friend, was an automatic choice for the film that features four heroes.
After two successive flops, Mumbai Se Aaya Mera Dost (2003) and Ek Ajnabee (2005) Apoorva hit pay dirt with Shootout at Lokhandwala. He attributes the success of the film to Viveik Oberoi, whom he now considers as his lucky mascot.
Consequently, Viveik too was an automatic choice for a lead role.
However, Viveik and Abhishek have a history named Aishwarya.
Apoorva must have hoped the wounds had healed now following the Abhishek-Aiswharya wedding. We are guessing he just didn't realize how deep the wounds were.