In 2011, there was a Conan the Barbarian reboot starring Jason Momoa as the titular character of Conan. It was a reimagining of the original 1984 adaptation starring Arnold Schwarzenegger that was based on the character of the same name who first appeared in pulp magazines of the 1930s. As the only survivor of a vicious massacre of his village when he was young, Conan sets out to get revenge on the warlord that murdered his father. Conan leaves a bloody trail across the land of Hyboria that becomes a battle of good versus evil when he finally encounters the object of his rage, Khalar Zym, the warlord king who seeks immortality.
The film received poor reviews from critics and was a box office bomb, but that didn't stop people from noticing the charisma of star Jason Momoa. It was his first major film role and is likely what influenced his casting as Khal Drogo on HBO's Game of Thrones that very same year. Momoa almost didn't get the role though. Had things been different, the theater would have been filled with devoted Supernatural fans. As it turns out, Conan was almost played by Sam Winchester himself, Jared Padalecki.
Most people only know Padalecki from the CW series Supernatural that ran for 15 seasons between 2005 to 2020, or for playing Dean Forester in the popular dramedy series Gilmore Girls. He got his start in films such as Flight of the Phoenix, House of Wax and Cry Wolf but is primarily a television actor. He pretty much stopped taking on movie roles around 2009; however, there was a brief moment in time when the Winchester bros, both Padalecki and co-star Jenson Ackles, appeared in major blockbuster horror movies around the same time Season 4 of Supernatural was airing.
Supernatural series creator Eric Kripke wanted to end the show after Season 5, and coincidentally, it was near the end of Season 4 when both Winchesters started auditioning for other roles. Padalecki starred in the Friday the 13th remake and Ackles in the My Bloody Valentine remake, which both came out in 2009. Friday the 13th, which released to mixed reviews but strong box office numbers, was directed by Marcus Nispel. Nispel didn't waste any time getting started on his next movie: Conan the Barbarian.
Padalecki auditioned for the role of Conan and was apparently one of the three final picks before Momoa was ultimately chosen. It was down to Padalecki, Momoa and Twilight actor Kellan Lutz who would go on to star in a very similar film, The Legend of Hercules, in 2014. There were rumored reports that Padalecki's schedule was too hectic to keep up with the filming of Conan the Barbarian, which had started in March of 2010. Season 5 of Supernatural had already begun filming by that point, so a schedule conflict seems like a good guess as to why he was eventually ruled out. There seems to be no officially released reason as to why he didn't get the part though. In the end, the movie was likely wouldn't have been a right fit for Padalecki, while his run on 15 seasons of Supernatural will forever be legendary.