Jordan Reid was Rob McElhenney's girlfriend at the time this pilot was produced. After FX picked it up, Reid and McElhenney broke up and she was replaced by Kaitlin Olson.
Morena Baccarin is a college friend of Glenn Howerton's and appeared in the pilot as a favor to him. A spray bottle was used to simulate her character's bulge.
In the original unaired pilot, the cast play struggling actors living in Los Angeles which they really were at the time. Carmen says that Rob was in an episode of Law & Order (1990). McElhenney really did make a guest appearance in a 1997 episode of the show.
This was their second try to shoot this episode. According to Charlie Day, the first version was "not good." In the first version, David Hornsby ("Cricket") played the role of Mac.