"I hear he's been working out," Rogen's "Pineapple Express" co-star James Franco told reporters in New York recently.
"I keep telling him. He doesn't believe me, though," Rogen, sitting beside him, said with a laugh.
"It's so unnecessary, though, because they'll just give you a muscle suit," added Franco, who co-starred in the three recent "Spider-Man" movies.
"It's true," Rogen agreed. "But there are a lot of shots of me, like, coming out of pools in slow motion. There's, like, 13 shots of that, so that's why I'm working out so much. What can I tell you? (My writing partner Evan Goldberg and I) have written it. We're meeting with directors right now."
They are shooting for a June 2010 release, Rogen said.
Asked if he knows who will play Kato, his titular character's sidekick, in the new superhero flick, Rogen replied: "No, not right now. Until we hire a director, it's kind of hard to cast the entire thing."