This 'Captain America' character will be in 'Avengers 4' mashable.com

Is this just a flashback or…something more? We know very little about Avengers 4 – other than that most of our faves are dead – but now we have a teeny, tiny nugget of intrigue.

Actor Frank Grillo, who played Brock Rumlow/Crossbones in Captain America: Winter Soldier and Captain America: Civil War, revealed that he returned to the MCU for an Avengers 4 flashback.