Zach Braff by Karen Neal/NBC
It looks like the upcoming Fletch prequel won't be the all-out Scrubs affair we had hoped for.

A scheduling conflict has forced Zach Braff to turn down the lead in Fletch Won, the in-the-works big-screen Fletch prequel that's being shepherded by Scrubs bossman Bill Lawrence.

"Zach is writing and directing his own film [ Open Hearts] at Paramount," says Lawrence, who's currently in New York searching for a new Fletch. "I'm very happy for him. We were looking forward to doing this thing together, but when you get an opportunity like that, you've got to take it."

But Lawrence and Braff won't be apart for long - in August they'll begin work on Scrubs' seventh (and final) season. The only question is which network it'll air on. Lawrence confirms that ABC, which owns the show, still plans on picking it up should NBC cancel it.

"I would've written a series finale [this season] if there was any chance the show was going to be canceled," he says. "I was going to end the show, and the good people at ABC basically said, 'The show's on ABC next year if it's not on NBC. Do not end it.' And as if to prove their intentions, they went and signed Zach up for a contract next year, which is ridiculously foolish if they weren't planning to pick it up. So I have every reason to trust and believe them.

"Right now, I would almost bet it'll end up on ABC for its last season," Lawrence adds. "But two weeks from now, when NBC gets [a look at] their pilots, it could shift."