Craig Ferguson

Craig Ferguson passed his citizenship test to become a U.S. citizen two years ago, but he may have more trouble joining another group: the cast of The Big Bang Theory.

Big Bang Theory extends hiatus due to Kaley Cuoco's injury

The geek-tastic cast is taking over Wednesday's The Late Late Show, which kicks off with the host interviewing to be the new friend of Sheldon (Jim Parsons), Leonard (Johnny Galecki), Howard (Simon Helberg) and Raj (Kunal Nayyar). (Noticeably absent is Kaley Cuoco, who's recovering from a horse accident.)

The Big Bang cast will then be featured throughout the Late Late Show, which includes guest interviews and a comedy sketch.

The Late Late Show with Craig Ferguson airs at 12:37 a.m./11:37 p.m. c on CBS. The Big Bang Theory returns Thursday at 8/7c on CBS.

Check out Ferguson's interview below: