The CW's Supergirl could have featured the return of Smallville star Tom Welling as Clark Kent aka. Superman as he confirms he turned down the role. Supergirl season 2 saw a number of changes for the small-screen Girl of Steel as the series moved from its original home of CBS to The CW. To kick off the show's new home in spectacular fashion, Supergirl finally introduced her superheroic cousin, Clark Kent aka. Superman. It was speculated whether Smallville's own Superman, Tom Welling, would return for the role, but eventually Tyler Hoechlin was cast as Superman.
Hoechlin joining the Arrowverse as Supergirl's Superman has been largely well-received by fans of The CW's shared superhero universe, and the actor has returned a few times since the Supergirl season 2 premiere. Most recently, Hoechlin appeared in the 2018 Arrowverse crossover, Elseworlds. But even as Hoechlin has become another beloved small-screen take on the Man of Steel, DC fans have wanted to see Welling return in some capacity, even if it's not as Superman. After all, the Arrowverse is set in a full multiverse of different worlds. However, it seems Welling may never appear as Superman in the Arrowverse since he's already turned down a return.
During a panel at the Armageddon Expo in New Zealand, Twitter user worldofmera (via CBR) revealed Welling confirmed he turned down being in Supergirl. It's possible this was a joke or taken out of context by panel attendees, since something similar happened with Welling jokingly confirming he'll be in Arrow season 8. But Welling confirming he turned down a role in Supergirl falls in line with what he's previously said on the topic.
In 2017, Welling addressed why he wasn't Superman on Supergirl, saying, "I would not want to watch me [suit up as Superman] at all." The actor also said the shows are too different in tone for it to make sense that Supergirl is set in the same universe as Smallville. Certainly, he has a point, since setting Supergirl in the same universe as Smallville creates continuity errors - especially since Smallville introduced its own version of Kara.
That said, fans would no doubt have liked to see Welling return as Superman from another world in the multiverse, much like John Wesley Shipp reprising his own Flash TV role from the 90s for the Elseworlds crossover (following two other roles in the Arrowverse, first as Earth-1's Henry Allen then Earth-3's Jay Garrick). The Arrowverse has included a number of former DC TV actors across its many shows, like Lois & Clark: The New Adventures of Superman stars Dean Cain and Teri Hatcher in Supergirl.
Fans and the Arrowverse creatives would no doubt like to see Welling appear in the TV franchise in some manner, but it seems the actor doesn't have any intention of doing so. Fans may be disappointed, but Welling played Clark Kent on Smallville for 10 seasons - that's a lot of time in one role and it's understandable he'd want to continue moving forward with his career instead of looking back.
Supergirl season 4 airs Sundays at 8pm ET on The CW.