'Avengers 4' Flashbacks Feature Crossbones, Frank Grillo Confirms [Updated]

Update 10/29: Frank Grillo walked back the statement, clarifying he "confirmed nothing."

Crossbones will return in Avengers 4 in a flashback sequence, actor Frank Grillo confirmed on the latest episode of UFC Unfiltered podcast with Jim Norton and Matt Serra. (Grillo's statements can be heard around the 19-minute mark.)

"He makes an appearance in the next Avengers movie, but it's a flashback. I'm allowed to say whatever I want because I'm never doing another Marvel movie," Grillo said.

Brock Rumlow, a.k.a. Crossbones, first appeared in Captain America: Winter Soldier as a SHIELD Agent in the STRIKE task force. He often teamed up with Cap and Black Widow, but it turns out he was a double agent for HYDRA all along.

crossbones avengers 4 flashbacks
Crossbones returns in 'Avengers 4.' Marvel

In the film, HYDRA orders Rumlow to find and capture Captain America and the Avengers. During one of the confrontations, a helicarrier crashed into the Triskelion (the SHIELD headquarters building in DC). Rumlow was trapped under rubble and severely injured.

After he healed, he adopted the moniker Crossbones, seeking revenge on Captain America for his suffering. In their final battle, Crossbones ignites a suicide bomb. Scarlet Witch saves Captain America in time, but Crossbones perishes in the explosion. There were multiple civilian casualties, including many Wakandan nationals, and the incident was one of many that lead the Avengers and government to adopt the Sokovia Accords — a set of regulations that restrict the jurisdiction of heroes in the Marvel Cinematic Universe.

It's unclear what Grillo means by "flashbacks." They could be straightforward flashbacks — for some reason, Thanos or Captain America might recall the events of Winter Soldier. But there's also the Avengers 4 time-travel theory, where the remaining Avengers travel back in time to figure out how to prevent the Thanos drama. Grillo did not specify in what capacity these flashbacks would take place.

Grillo joined the UFC Unfiltered podcast to talk about his new Netflix series Fightworld. "I traveled around the world and embedded myself in fight culture," he said. "It's not a tutorial about fighting. It's about the culture of fight in each place."

Avengers 4 arrives May 3, 2019. Fightworld is now streaming on Netflix.