Fuller House brought back some of DJ's ex-boyfriends from Full House including Nelson who was subtly recast for the Netflix spin-off series.

Fuller House subtly recast one of DJ's ex-boyfriends from Full House — why? The Netflix spin-off series brought back the original cast of the late '80s/early'90s sitcom, except for Michelle as Mary-Kate and Ashley Olsen refused to partake in the project. But, to further drive nostalgia, it also featured a string of familiar faces throughout its run, including Nelson — one of DJ's former flames, Nelson Burkhard.

Towards the end of Full House season 7, DJ and Steve were having problems with their relationship. While the couple was still attracted to each other, Steve's decision to go to college in Florida put a strain on their relationship. DJ struggled with their long-distance setup and was increasingly becoming dispassionate about their romance. By season 8, Nelson was introduced; the son of a very rich man, he didn't have any issues wooing DJ using his father's money which sat well with Kimmy, Stephanie, and even Michelle. Nelson was hopelessly in love with DJ, but their affair didn't last long as she's not that attracted to him. Despite that, Nelson still hung around as he not only maintained his friendship with the eldest Tanner daughter, he also began seeing Kimmy. 

Since Fuller House really leaned on nostalgia for its storytelling, it brought back as many old characters from Full House. Nelson aptly returned in Fuller House season 2, episode 11 titled "DJ and Kimmy's High School Reunion," alongside another one of DJ's exes, Viper and Kimmy's former flame, Duanne Moffat. But while the latter two were played by original actors, David Lipper and Scott Menville, the spin-off had to recast Nelson who was initially played by Jason Marsden. Instead, Hal Sparks was brought in to play the character. As it turns out, Fuller House did reach out to Marsden for a guesting spot, however, the actor decided against reprising the role. He didn't get into any specific reason why, he was very supportive of his replacement. 

Interestingly, this was the only time that Nelson appeared in Fuller House despite the return of Viper and Duanne in the series finale. For the spin-off's ending, DJ, Stephanie, and Kimmy all got married at the same time to Steve, Jimmy, and Fernando, respectively. No word on whether or not Sparks was invited to reprise his role as Nelson. Considering his resemblance to Marsden, Fuller House totally nailed recasting the character, so it's curious why the Netflix series didn't take advantage of it more.

Since appearing in Fuller House, however, Marsden has been involved in other projects such as a guesting stint on Grey's Anatomy season 14 and Famously Afraid. Meanwhile, Marsden has also done a lot since retiring his Full House role and refusing to reprise it in its spin-off. Marsden was the voice of Thackery Binx in Hocus Pocus, but having not appeared in a live-action movie since 2012, he is most known for voice-over work. He is now officially the voice of Max Goof (son of Goofy) and is the voice of Bart Allen/Impulse/Kid Flash II, Ray Palmer/Atom on Young Justice: Invasion.

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