Michael Cera Michael Cera

The long-awaited Arrested Development movie is happening — but it's currently arrested in development by one of its own.

Michael Cera, aka George Michael Bluth, is the sole cast member who has yet to sign on to the big-screen feature, E! Online reports.

"I know he's thinking about it," Jason Bateman said while promoting his new animated Fox series, Sit Down, Shut Up (premieres April 19 at 8:30 pm/ET). "And we're all awaiting some finality to all of that so Mitch [Hurwitz] can get writing."

Bateman, who turned 40 on Wednesday, clarified that Cera has not turned down the role reprisal yet, adding that he understands why the Superbad star is super wary about reuniting with the dysfunctional Bluths.

"I think Michael is clearly the guy that has come out of Arrested Development with a very big plate, so I think he's trying to really give some responsible thought to what makes sense for him to do with his career," he said. "The guy is 20 years old and I'm sure he doesn't want to screw up this opportunity."

If Cera does not come back, it will put a damper on Hurwitz's premise for the flick. Although he toyed with the idea of a prequel, featuring a kid CG version of Cera, Hurwitz, also a producer on Sit Down, Shut Up, said his plan now is to jump ahead in time.

"We're going to pick up five years later, and family dynamics change, but they also kind of stay the same," he said. "So hopefully we'll just explore where they are now."

Why do you think Cera's holding out? Will he sign on? And hasn't he basically been playing George Michael ever since the show ended?