According to Variety, Elba will be playing an unknown new character. The decision was reportedly made not to "disrespect" Will Smith, who first played the character.
Since the"Men in Black" star left the franchise due to a scheduling conflict, that leaves the door open for Smith to return as Deadshot for future installments.
So far, the only confirmed returning stars from the 2016 film are Jai Courtney as Captain Boomerang and Viola Davis as Amanda Waller. Margot Robbie is expected to be back as Harley Quinn, but no official announcement has been made.
Gunn is in the process of casting the rest of the squad. Production is expected to start in this fall, for a release date of August 6, 2021.