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Lindsay Lohan apparently has the jitters ahead of her first big acting gig since leaving rehab.

The 28-year-old is preparing for her stage debut in a London production of David Mamet's "Speed-The-Plow" and admits being worried she'll "mess up" her first night on stage.

"I think it's just the idea of when it starts, on opening night, that's what makes me the most nervous," Lohan told UK's Daily Mail. "I'll probably mess up on the first night just out of fear."

The show opens Sept. 24 at London's Playhouse Theatre, and Lohan begins rehearsals later this month.

"I'm excited about the rehearsals, I'm going to be nervous at first obviously, even in the rehearsals. But I think the more I get comfortable on the stage in rehearsals, the better it will be. I'm nervous for the show. I'm scared," the "Mean Girls" star told the newspaper.

And it's not just because Lohan has never been on stage before. Though she's been acting since age 3, Lohan revealed she's never had any formal lessons.

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"I've never done a play before. I've never even taken acting lessons," she said in the interview. "I've never done anything like that and it's something new to me and it's live."

But for Lohan, who has spent more time in rehab and courtrooms than in front of the camera in recent years, the challenge is welcome.

"Now I'm in a position where I want the diligent schedule, I want to do something different and have people see me as an actress on stage and that's all they see because I got into this to be an actress," she said. "I hope that with doing this play and working with people that I really admire and respect that the perception can maybe shift onto not Lindsay the tabloid person but to me as an actress which is what I started this for. It's therapeutic for me, acting."

The change of scene - Lohan left New York for London to escape the notoriety of her OWN reality show - has also been good for Lohan.

"I moved to New York to find peace and I wanted to do something very real and show people who I am, and because it's a reality show it had to be done a certain way, and things had to look a certain way for ratings," she told the Daily Mail. "That wasn't my intention of moving to New York. I again got overwhelmed with that and wanted to get away for a minute and I came to London."