Just when you thought the cast of James Gunn's The Suicide Squad was thoroughly stacked, it grows by one. This weekend, Gunn casually revealed that Sylvester Stallone had joined the cast of The Suicide Squad. Stallone's casting marks a reunion with Gunn after the veteran actor appeared in Guardians of the Galaxy Vol. 2 as Stakar Ogord. Stallone joins an impressive cast, including Margot Robbie, Idris Elba, Jai Courtney, Joel Kinnaman, Viola Davis, and John Cena.

On Saturday, Gunn hopped on Twitter and Instagram to share a new set photo featuring Stallone and himself on the Suicide Squad set. Gunn captioned the photo thus: "Always love working with my friend @officialslystallone & our work today on #TheSuicideSquad was no exception. Despite Sly being an iconic movie star, most people still don’t have any idea what an amazing actor this guy is."

The set photo doesn't reveal too much about how Stallone figures into the gritty, weird, and wild world of The Suicide Squad. Just as irksome (for the purposes of sleuthing) is the fact that Stallone doesn't appear to be in costume, so it's hard to get a read on his role or relationship to the other characters. The set shown in the photo seems to be of a flashy bar or club, which might hint at where in The Suicide Squad he'll pop up. But, just like Gunn's tease that no character is safe, it seems all bets are off when it comes to Stallone's involvement in this upcoming Warner Bros. movie.

The Suicide Squad is set to hit theaters on August 6, 2021. Check out Gunn's set photo featuring Stallone below. For more, get the latest updates on the Suicide Squad spinoff show Peacemaker and check out what Jai Courtney told us about the new DCEU movie.

Allie Gemmill is the Weekend Contributing Editor for Collider. You can follow them on Twitter @_matineeidle.