Charlie Hunnam is well aware of the mixed reactions he's been receiving from fans in response to being cast as the S&M-crazed billionaire Christian Grey in the movie adaptation of Fifty Shades of Grey.

While a fair share of his naysayers have pulled no punches while dishing their concerns, a couple of the English actor's castmates on the TV Series Sons of Anarchy were very confident in not only his abilities, but also his true dedication to the groundbreaking role.

Maggie Siff, who plays the 33-year-old's onscreen wife Tara on the TV series, recently told Entertainment Weekly about her initial reaction when she first heard the shocking news.

"When he told me that it was happening or that he was considering it, I just howled. I mean, I think we all did. We're all like, What?"

Although the cast and crew couldn't help but give Hunnam a bit of a hard time, the actress said they eventually gave him serious input on the sexy task ahead.

"Then I talked to him seriously about it. I think he's very brave to do it. He doesn't do anything unless he feels it deep down. He's not going to do something because all of his agents are telling him to do something. That's what makes me think it stands a chance of being really, really great," Siff added.

Katey Sagal, Hunnam's onscreen mother Gemma, also elaborated on the star's casting in the racy film, saying she's still up in the air on whether she'll check him out in the buff.

"The choice was not an obvious one for him, but for good or bad, he will throw himself 100 percent in. I don't know if I want to see all that, but maybe," she said.

Hunnam can currently be seen on the sixth season of Sons of Anarchy on the FX network. Fifty Shades of Grey is scheduled to debut on the big screen on Aug. 1, 2014.

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