Potential spoilers for Supergirl ahead!
Even though the upcoming TV show Supergirl is starring Kryptonian Kara Zor-El, there has hasn't been much said about her significantly more famous cousin Superman. Although the original series premise mentioned Kara's relationship with him, no other information has been provided on what role he'll play in the CBS series, if any. Superman is already busy with his own adventures on the big screen, so no one needs to worry about him losing any attention, but new information has been leaked that suggests that he'll also have a crucial part to play in Supergirl…well, his reputation, at least.
New videos have surfaced online (via ComicBookMovie.com) showing various actors auditioning for the roles of Kara, Kara's sister Alex and Jimmy Olsen, who in the comics is a photographer at The Daily Planet and Superman's "pal." During several of these videos, Superman is discussed at length, such as Jimmy reminiscing about when he saw the Man of Steel swing the tenants of a burning building. The dialogue from these audition scripts may not match the lines we'll eventually hear on the show, but it sounds like Superman will maintain an important presence in the series. By the time Kara "goes public" with her powers, her cousin is already well established as a famous superhero (or perhaps the only superhero if this world doesn't include other people with special abilities).
Given that DC has decided to keep their movie and TV universes separate, it's unlikely that the DC Cinematic Universe's Superman, played by Henry Cavill, will be the one characters frequently talk about. This also begs the question of whether we'll ever see Superman in person on the series. The biggest problem with including him is his presence inadvertently overshadowing the titular protagonist. Kara is powerful enough to handle most threats on her own, but what happens if she faces an enemy that's out of her league? If this was the comics, unless he's off-planet or indisposed by another enemy, he would probably rush in to save her and help defeat the bad guy.
While it would eventually be nice to see Kara and Kal flying alongside each other on the small screen, Supergirl will have to create a suitable explanation for why he isn't showing up every other episode to hang out or jump in with an assist so the protagonist can get the attention she deserves. Let's have only one Kryptonian shining the spotlight for the time being. Maybe he was cleaning the Fortress of Solitude, accidentally turned on the Phantom Zone projector and got trapped in the ghostly dimension. That should keep him out of play for a few seasons.
