Leighton Meester replaced by Andrea Estella in 'Veronica Mars' Movie

Leighton Meester will not be appearing in the upcoming "Veronica Mars" movie.

After weeks of speculation series creator Rob Thomas announced Sunday that the former "Gossip Girl" star won't be reprising her role as Carrie Bishop as she is "unavailable" at the moment. He added that singer Andrea Estrella of the band Twin Sister will take on the role instead.

Meester played the role of Bishop during two episodes in the first season of "Veronica Mars," a UPN/CW series that ran from 2004 through 2007.

On Sunday Thomas told the movie's Kickstarter backers that even thought he wanted Meester to reprise her role as Carrie Bishop, she would not be able to do so.

"Sadly, Leighton was doing a different movie during the same time frame on the wrong coast," he wrote. "In the end, she was unavailable.

"One of the reasons I wanted Leighton, beyond her talent/beauty/history in the show, was that we needed a performer who could sing in this important role. Once it became evident that we couldn't make Leighton's schedule work, I decided to cast someone from a band I already wanted in the movie."

Four months after raising $1 million in a little after four-hours, the "Veronica Mars" movie is already in production in Los Angeles.

Estrella, who had never seen an episode of the show before being cast by Thomas because of her "amazing voice," said the whole thing was a dream come true.

"I watched the Veronica Mars pilot and was totally into it!" she wrote. "It's the exact kind of show I would get obsessed with, so it's been a bit of dream to be in a movie, especially being a messed-up rock princess. How could I say no? I think the VM fans are going to be very happy!"