While Kurt Russell's Guardians of the Galaxy Vol. 2 role as Ego, the Living Planet was revealed early on in the build-up to the movie, the role Sylvester Stallone is playing has been kept under wraps - but an movie news website in Italy now claims that Marvel Studios has named the character.
According to MoviesBook, Stallone is playing Starhawk - one of the earliest Guardians of the Galaxy in comic book lore. In comic books, Starhawk is the son of modern-day heroes Quasar and Kismet - and there as been wide speculation that Elizbaeth Debicki's Guardians Vol. 2 character Ayesha is based in part on Kismet.
Writer/director James Gunn has stated that Stallone and Russell are both "a big part of the MCU now," and that Guardians Vol. 2 wouldn't be their only time appearing in the MCU. Gunn also stated that Smallville alum Michael Rosenbaum's character, also unrevealed, "sort of works in tandem" to Stallone's character.
Guardians of the Galaxy Vol. 2 is due out in theaters May 5.