Marvel's highly-anticipated Avengers 4 continues production in Atlanta, with the latest set photos revealing that Thor's long hair is now back, after the events of Thor: Ragnarok. Earlier today, though, star Robert Downey Jr. sent out a new photo on Instagram, from a local Atlanta theater where the star and several of his Avengers co-stars are putting on a one-night-only production of the iconic play Our Town. Robert Downey Jr. himself will be starring in this production, along with Mark Ruffalo and Scarlett Johansson and a host of unnamed local actors, but perhaps the biggest surprise in this photo is that it also features Frank Grillo, which could mean the actor is bringing his Crossbones character back from the dead.

Frank Grillo only appeared in two MCU movies as Brock Rumlow, a.k.a. Crossbones, but he certainly did make an impact with the scenes he was given. We last saw Rumlow in his full Crossbones costume towards the beginning of Captain America: Civil War, when he activated a suicide bomb within his own suit, trying to take out Steve Rogers (Chris Evans), although Scarlet Witch was able to use her powers to contain the blast somewhat, and while Rogers' life was saved, many more still lost their lives. While there has never been any indication that the producers were looking to bring Crossbones back to life, Frank Grillo's appearance in this seemingly innocuous photo, taken at Atlanta's Fox Theater, has many wondering if Crossbones is in fact coming back from the dead.

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Crossbones certainly wouldn't be the first character to come back from the dead within the Marvel Cinematic Universe, but given the rather explosive nature of his death, his potential resurrection would be among the most unlikely out of the deceased characters within the MCU. Still, even if he does come back, it remains to be seen how he would be brought back into the fold, with Avengers old and new focusing their efforts on defeating the greatest threat ever seen in the MCU, the Mad Titan himself, Thanos (Josh Brolin). It's possible that Crossbones may be brought back to life by Thanos himself, or that he could be used for a flashback scene, but still, his involvement in the movie has not been confirmed, and it likely won't be.

There could be a multitude of other reasons that Frank Grillo is in Atlanta, which has become quite the production hub for Marvel and other studios over the past few years, but his presence in this photo along with several other Marvel actors is certainly intriguing. Regardless of his potential Avengers 4 connection, local Atlanta theater fans are certainly in for quite the treat tomorrow night, with a cast filled with A-list movie stars and other local actors putting on Thorton Wilder's Our Town. Hopefully after the play, we'll get more conclusive proof regarding Frank Grillo's involvement in Avengers 4.

This photo also comes just a few weeks after we got word that the Avengers 4 cast has gotten another interesting addition. Ty Simpkins, who played the young character Harley Kenner in 2013's Iron Man 3, has been set to reprise that role in Avengers 4. While that was never confirmed from Marvel Studios, the news did come from the IMDB Twitter account, so it very well comuld be reliable information. As for the Frank Grillo/Crossbones connection, we likely won't get any confirmation one way or another. Take a look at this phto below, courtesy of Robert Downey Jr.'s Instagram.