Michael Sheen has revealed he had hesitations about starring in Masters Of Sex, because it involved signing a long contract.
The Welsh star, who has been living in Los Angeles for the past 10 years, has committed himself to a seven-year deal to portray American obstetrician Dr William Masters in the Channel 4 drama.
"I had doubts about signing a seven-year contract. It's a big commitment," he told the Radio Times.
Michael, who stars in the show alongside Lizzy Caplan, said he relishes the opportunity to portray a real person in Dr Masters. The 44-year-old is best known for his portrayals of former British Prime Minister Tony Blair, TV presenter David Frost and football star Brian Clough.
"I like having a real life to explore," he said.
"You have to search for what connects you to them, whereas when you are dealing with a fictional character, the life you develop inevitably comes from within you," he added.
Masters Of Sex continues on Tuesdays on Channel 4.