Skrulls In The MCU
The origin of the Marvel Cinematic Universe was an attempt to allow blockbuster superhero films to mirror the storytelling of comics. Characters could crossover from one film to another, and all of the events of each movie would exist in one cohesive world. What's more, massive team-ups and interconnecting stories could be introduced. The Avengers proved this plan was a critically and financially viable option, and Avengers: Infinity War is set to push the idea even further. But another important aspect of the MCU is its extension outside of cinemas.
While the Marvel-Netflix shows and Runaways operate in their own little corner of the MCU, Agents of S.H.I.E.L.D. was instigated by The Avengers. Though the films have yet to acknowledge the events or stories from the show, the series has regularly based its narrative on the fallout of the films. Captain America: The Winter Soldier created an entirely new status quo for the series, and Thor: Ragnarok and Guardians of the Galaxy inspired Agents of S.H.I.E.L.D. to go cosmic this season.
Even after the Kree were announced as a big part of Captain Marvel, Agents of S.H.I.E.L.D. has still been free to make them the central protagonists of the first part of season 5. The future setting of the show also means they can skip a lot of the groundwork of setting up a story based on the films. One of the chief issues the average moviegoer has the MCU (or any shared universe) is how much they need to know about other films. Because of this, the idea of a multi-tiered invasion slowly unfolded on Earth might be something better suited for the prolonged and serialized nature of a TV show. Of course, there's still one big problem: this may be Agents of S.H.I.E.L.D.'s last season.
Every year, fans are both surprised and relived when Agents of S.H.I.E.L.D. gets renewed. The series' ratings have never been that strong for an ABC show, though its critical acclaim has increased with each season. When it came to season 5, word is Disney helped save Agents of S.H.I.E.L.D. from being cancelled. But despite all that, most people believe this will be the show's last gasp. If that's the case, it's hard to imagine the show introducing a massive Skrull-based plot before Captain Marvel even hits theaters in 2019.
If Agents of S.H.I.E.L.D. does get at least one more season, then this year could easily see the conflict with the Kree slowly introduce one involving the Skrulls. The future setting could tease their chaos, while the actual Skrulls could debut in the past/present once the agents return inevitably return home. Most excitingly, but the show could reveal that one of the agents is a Skrull in disguise, something that would be able to play out much more dramatically than in a film. With the groundwork laid, Agents of S.H.I.E.L.D. could go full-blown Secret Invasion in the back half of its hypothetical season 6 after Captain Marvel debuts in March of 2019.
Assuming Agents of S.H.I.E.L.D. can last for at least another season, the precedent and setting is there for the show to tackle Secret Invasion. With all the characters and plots the films have to choose from, there's no guarantee something as far-reaching as Secret Invasion could make its way to the big screen. But Agents of S.H.I.E.L.D. has proven its the perfect platform to introduce the Skrulls and give life to their most famous story arc from the comics.