The "Grease" star plays Simpson's lawyer Robert Shapiro in the much-anticipated TV show and he said it took him some time to agree to appear on the small screen, reported Contactmusic.
"Initially I thought, 'Why are they doing this? Is it a guilty pleasure? Is it going to be sensational..."' he said.
"And I was offered a position as a producer to ensure the quality of the project if I wanted to, but with Ryan Murphy... these people only do high-end things. I surveyed a lot of my top friends in the industry to see what they felt and they felt like TV was really coming around to be the place where adults go to watch things... And it is multi-layered...