With the help of a combover, mustache and print-filled wardrobe, the Walk Hard: The Dewey Cox Story star transforms into the self-made millionaire and majority owner of the Lakers during the team's Showtime era.
Prior to Reilly joining the series, Michael Shannon was set to portray the larger-than-life Dr. Buss, but he dropped out due to creative differences. "It really bugged Michael that we were breaking the fourth wall," executive producer Adam McKay explained to The Hollywood Reporter. "He kept saying, ‘I don't like this. It throws me. I'm having a hard time.'"
The casting decision would end up causing the ongoing rift between McKay and longtime friend and collaborator Will Ferrell, who expressed his interest in playing Buss and only learned Reilly would be taking over the part after he received a call from his Stepbrothers co-star.
Looking back, McKay admitted to THR that he "f--ked up" by not reaching out to Ferrell beforehand.
"It was at this weird moment where Will and I weren't exactly hugging each other, even though there was nothing that terrible and he called Will and said, 'Hey, McKay just came to me with this,'" McKay recalled. "And Will was very hurt that I wasn't the one to call him, and I should have."
Reilly, meanwhile, said, "Will is one of my best friends, Adam is one of my best friends, I was delighted to get the job and that's all I really have to say."