Things didn't work out between the former couple when Salman Khan and Aishwarya Rai Bachchan were meant to work on THIS movie with Sanjay Leela Bhansali.
According to reports, Sanjay Leela Bhansali had hoped to make Bajirao Mastani with Salman Khan and Aishwarya Rai Bachchan, then-Bollywood's most adored Jodi. However, after the bitterness in their relationship, Aishwarya nearly made it impossible to even work with Salman on any projects as she had severed all ties with him. Salman requested that SLB replace Ash with Katrina Kaif as his Mastani.
According to sources, Salman Khan walked straight to Bhansali's office with Kat and stated that she is your Mastani since he was furious that he couldn't even get Aishwarya to work with him on a movie. Even though SLB wasn't sure Katrina was his Mastani at the time, he had given up the notion and had no idea the movie would ever be made.
However, Ranveer Singh and Deepika Padukone are today's Bajirao Mastani; destiny had saved this movie just for them. Later, they even worked with SLB on two additional films, Ram Leela and Padmaavat, which were also eagerly anticipated due to their casting.
In one of his interviews, Sanjay Leela Bhansali explained why this movie chose Ranveer, Deepika, and Priyanka Chopra. He said, "Today who would expect Ranveer and Deepika to be a part of the cast, 12 or 15 years later. They must be in school when I announced the film. It was Salman first and it didn’t work out."