United Kingdom, Oct. 13 -- Matthew Rhys is "terrified" about playing Richard Burton on stage in a new one-man play.

The Americans star has taken on his first stage role in 13 years by signing up for the lead in Playing Burton - which opens at The Old Vic in London on Sunday (16.10.25) - and he now admits he's fretting about forgetting his words and worrying about whether to imitate the late actor's voice.

Rhys told The Times newspaper: "Yup, I'm terrified. And the fact that I will be entirely by myself on stage makes it even more daunting.

"If I forget my words I will be truly at sea. But this is what I originally trained to do, so I guess it's like giving my acting technique a kind of MoT.

"You know, how are the old muscles working a...