Frank Grillo continues to tease Crossbones' return to the Marvel Cinematic Universe in Avengers 4. Fans of the MCU may now have new material to sift through with Ant-Man and the Wasp in theaters, but there's still plenty of attention being given to what next May will offer. Half of the universe is dead thanks to Thanos' infamous snap. Making things potentially even tougher on the heroes is a new theory that Thanos may have traveled through time at the end of Avengers: Infinity War and now is resting up on an older Titan.

If that is the case, it lends even more credence to the line of thinking that Avengers 4 will be a time-traveling film. There's multiple theories that explain why the heroes will take this path. However, the other noteworthy part of this type of storytelling is the ability it gives Marvel to play their greatest hits over again. This could result in recreations of their biggest scenes, and maybe even the return of a few otherwise unavailable characters.

Related: Is Crossbones Returning for Avengers 4?

One of these characters may just be Brock Rumlow aka Crossbones, played by Frank Grillo. He initially teased "really interesting" news about Crossbones' future late last year that sparked rumors of his possible return. In a new Instagram post, Grillo is either playing into these theories to mess with fans or giving further evidence that he's returning next year. The picture isn't the clue, it's his choice of hashtags. He includes ones for his two MCU appearances, #CaptainAmericaTheWinterSoldier and #CaptainAmericaCivilWar, but finishes the caption with #Aven........... - see it below:

If we really want to dive deep into the post, his Avengers hashtag has enough dots to spell out #AvengersEndGame, which is the rumored Avengers 4 title, and features several action figures from Infinity War in the background. The character count in the final hashtag could just be a coincidence after all, and there are also Star Wars toys on the surface, so this isn't Grillo quietly revealing an Avengers 4 scene. As mentioned prior, though, Grillo could just be messing with everyone, but there have been enough teases before that make this return seem plausible.

Rumlow was set up to have a larger role after The Winter Soldier, but the decision to go with the Civil War storyline shortened his stint. As a result, Grillo only got to appear at the beginning of Civil War. Whether he'll return during his Winter Soldier or Civil War days, there's a chance to give him one more appearance. If Crossbones does appear, though, it shouldn't be expected to be in a large capacity. Crossbones will still be dead when Avengers 4 comes to a close, unless it introduces the idea of changing the present as the heroes travel throughout time. Given the secrecy surrounding the entirety of Avengers 4, we shouldn't expect confirmation on Grillo's role anytime soon, if ever.

MORE: There's No Way Avengers 4's Time Travel Will Make Sense

Source: Frank Grillo/Instagram

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