Crossbones could be making a Marvel Cinematic Universe comeback, according to actor Frank Grillo, who is once again teasing his return in Avengers 4. Even as Ant-Man and the Wasp hits theaters and as Captain Marvel continues to film, Avengers 4 is still the major topic of discussion amongst fans of the MCU. That being said, Crossbones is dead, so if Frank Grillo is being truthful, some time travel will have to be involved to bring the character back, which has been heavily rumored ever since Infinity War opened in theaters.

Frank Grillo took to social media to once again tease an appearance of Brock Rumlow, aka Crossbones, in Avengers 4. The actor posted a photo collage of his Crossbones action figure fighting with Captain America while some other Infinity War action figures mixed with Star Wars figures watch the battle unfold on Instagram. While the collage of action figure battles doesn't really suggest a return of Crossbones, it's Grillo's use of hashtags that begins to hint at a few things.

First of all, Frank Grillo puts Winter Soldier and Civil War in hashtags, for the two movies that he portrayed Crossbones in. Next, he begins to spell Avengers, but only places the first four letters, written: #Aven........... Obviously Grillo is strongly hinting at his appearance in Avengers 4. Upon closer inspection, the Avengers hashtag has enough dots to spell out Avengers: End Game, which is the rumored official title for the movie. These dots could all just be a big coincidence or Grillo is teasing something much larger. One can imagine that Marvel Studios isn't too happy about Grillo's actions at the moment, if he is actually in the film.

Marvel Studios keeps things very close to the vest while they're making and releasing their projects, so it seems pretty odd that Frank Grillo would be teasing so much. Number one, it hints at time travel since his character is dead within the MCU. Number two, it gives further hints into the title, which will send some hardcore fans into crazy speculation mode. And while it all might be true, Marvel Studios isn't going to come out and confirm the news, so we'll have to wait until next May to see if Grillo made the final cut.

Even if Crossbones makes an appearance in Avengers 4, it won't be that big of a part and will more than likely be just a small cameo. Crossbones was last seen in Civil War before he blew himself to pieces and took down innocent people with him. This is quite different than the tone that Frank Grillo had about a return to the MCU in early 2017. When asked about a possible comeback, the actor said that he was not interested. Again, we'll just have to wait and see what happens when Avengers 4 opens next May. For now, you can judge for yourself while looking at Frank Grillo's Instagram account.