Chris O'Dowd is in talks to join the Knocked Up spin-off, known as This Is Forty.
In the comedy sequel directed and produced by Judd Apatow, Leslie Mann and Paul Rudd will reprise their roles as Debbie and Pete five years after the last film.
Megan Fox, Albert Brooks, Charlene Yi, Lena Dunham and Wyatt Russell are also being linked to the film, reported Variety.
Chris, who next appears in Bridesmaids with Kristen Wiig and Rose Byrne, and Lena would play employees at the record label Pete runs, while Wyatt would be a hockey player.
Charlene is expected to reprise her part as stoned-out girlfriend Jodi, while Megan's turn is still unknown. Albert would be Pete's dad.
Filming will begin in the summer, with a release slated for December 2012.