"We faced roadblock after roadblock, went through hell to find someone to blindly believe in our film. We literally struggled to get this film made," Sudha told IANS.
Hope came in the form of actor R. Madhavan, recalls the director. She approached him with the script in 2011 when he was shooting for his Tamil film "Vettai".
"He told me he would tell me in 48 hours if he would do it. Exactly 48 hours later, he called and told me, 'What a script you've written! I'm on'. But I told him I didn't have a producer and I wanted the film to reach out to people and for that to happen, we should take it to the right people."
"He told me, 'Sudha, you've given me the best script and see where I take you'," she said.
Madhavan was instrumental in bringing on board his "3 Idiots" filmmaker Rajkumar Hirani, who has produced the film in Hindi.
"Without Rajuji, this project would have been a small film. Our last producer literally dumped us midway and when things were going from bad to worse was when Rajuji stepped in," Sudha said.
Hirani's association with the project came as a big boost, she added.
"He's right there up next to god for me as far as I'm concerned. I'm eternally grateful, because he sent me a message long back which read: 'You have a great story. Don't worry about anything. I'll do everything in my power to make it happena'. And he made it happen," she said.
For Sudha, who has previously made films such as "Andhra Andagadu" and "Drohi", Madhavan was always the first choice for the lead role of the boxing coach.
"I've known him for over a decade and there's this inherent inane arrogance and attitude in my coach, which I thought was always there in Maddy. I've seen that side in him more than anybody. It was far too evident," she said.
Even before the project went on the floors, Sudha spent about three years on research work.
"I met with several boxers, coaches and officials from all over the country. Every scene is from the character I've met and spoken to on this journey. There's so much drama in the lives of boxers. It's a contact sport and everyday they beat up people for a living," Sudha said.
"All these things became the material for my script," she shared.
The pre-production and the shooting of the film took three more years.
"We started shooting in August 2014 and by November, Madhavan had to go to shoot 'Tanu Weds Manu Returns', and we still had six days of shoot. So, he had to get out of his get-up, cut his hair, lose weight, go do another film and come back and finish my film."
"He finished shooting 'Tanu Weds Manu Returns' by April 2015. He spent the next few months getting back in shape, growing his hair again and joined the shoot only in September," she said.
Sudha admits that it was Madhavan's enthusiasm more than hers that kept everybody motivated.
"Saala Khadoos", which also stars debutante Ritika Singh, releases in cinemas on Friday. It also releases in Tamil as "Irudhi Suttru".