From the beginning, it's been clear that the Supergirl series wants its heroine to remain front and center, despite her famous cousin. The show doesn't avoid the connection, explaining right from the pilot episode how Kara Zor-El (Melissa Benoist) was meant to be Kal-El's protector. Her late arrival on Earth meant he became a superhero without her, and she was left to find a new life as either a regular girl or a hero in her own right.
Superman (and his alter ego Clark Kent) exists in Kara's world, but he's been kept mostly offscreen, and is only a blurry or half-seen figure when he does appear. Usually his presence is felt as pressure for Supergirl to live up to his heroic success. We get a more personal connection through photographer James Olsen (Mehcad Brooks), friend to both the cousins, and Clark is only a text message away when Kara wants to catch up.
This February, an episode of Supergirl will feature a teenage Kal-El, offering another way to build up the family relationship for viewers without interfering in the adult Kara's current superhero adventures. It still seems plausible that we'll see a future team-up to save the world, and just the hint of that possibility turns into speculation on who would be cast as Kara's cousin. Those who have played the character before, on the big and small screen, are the first to come to mind, and that includes former Smallville star Tom Welling.
Smallville began in 2001 on The WB, which morphed into The CW during the show's ten-season run. Detailing Clark Kent's pre-Superman life as a teenager, then an adult at the Daily Planet, the series chose to focus more on the humanity of the characters than costumed heroism. This more in-depth, emotional look at DC comic book icons made Smallville an influential predecessor to the current crop of superhero TV series like Arrow, The Flash, Gotham, Daredevil, Jessica Jones, and of course, Supergirl. In an interview with Buzzfeed, Welling revealed he was pleased to have left a lasting impression with his long-running show.
"It’s a compliment. I’m very proud of shows like Arrow [and] The Flash. … They’re able to ground these characters so that the viewer can relate on a human level to people who used to be only in two dimensions."
So what does the actor think about taking on the Clark Kent character again for a new role on Supergirl? As someone who felt he and his fictional alter ego "grew up together," Welling told Buzzfeed writer Jarett Wieselman that he isn't sure how his version of the character would work on the new show.
"There's people who would like it... there's people who don't like it, but I will tell you that no one has ever actually asked me to do it. So, I don't know. It would be kind of odd. I don't know who he is at that point. He would obviously be Superman..."
While he hasn't yet been invited to participate, Supergirl has proven it has no problem casting actors already familiar with the roles. The pilot revealed Dean Cain of Lois & Clark and Helen Slater of the 1984 film Supergirl as Kara's adoptive parents, and the two have featured in subsequent episodes. Welling's Smallville Superman would certainly be able to identify with Kara's struggle to transition from normal girl to superhero, and fans of the original series would love to see their favorite character back on the small screen.
If Supergirl does decide to cast an adult Superman, however, it's likely they'll want someone who can continue to play the role as needed on this series and any potential crossovers with other DC character shows. The full interview with Welling reveals he invested a lot of time and personal sacrifice in Smallville, and it took a lot of convincing to get him to return to TV at all, let alone revisiting the same character. So while it may be fun to conjecture whether Welling's Clark would work in this Supergirl universe, at this age, it's probably not going to happen.
Supergirl continues this Monday at 8pm on CBS with epsiode "Bizarro".