He's been the voice of Shaggy on Scooby Doo, Where Are You? for 23 years, but Casey Kasem isn't expecting to land a part in the upcoming live-action movie version of the popular cartoon series.

"I'd love to have a role, but I doubt it," the veteran radio host and voiceover actor tells TV Guide Online. "Instead of using the voice actors, they'll probably just have the actors do it the way they would do it."

Freddie Prinze Jr. and Sarah Michelle Gellar are said to be in talks to play young sleuths Fred and Daphne in the big-screen Scooby. Meanwhile, Matthew Lillard, the killer in the first Scream, has been linked to the role of Shaggy, their happy-go-lucky hippie bud.

Regardless of who lands the plum part, Kasem says he's happy for Scooby's long-running success. "I think it's bigger today than it's ever been," says Kasem, who has provided voices for cartoon characters ranging from Peter Cottontail to Robin the Boy Wonder. "They found a wonderful formula, and it worked."

Kasem and his actress-wife, Jean, best known for her role as Loretta Tortelli on Cheers, are busy these days finishing up a three-year renovation of their L.A. home. They've also just opened a retail store in Beverly Hills, the Little Miss Liberty Round Crib Company, offering uniquely designed baby cribs.

Someday, Jean says she'd like to co-star with her hubby in a sitcom, but Casey insists he's not a very funny guy. "That I'm not," he says with a smile. "I would not want to do a sitcom — that will never happen."