"Avengers: Infinity War" will feature the return of Gwyneth Paltrow and Jon Favreau.
"Infinity Trinity ... #infinitywar and street cred @jimmy_rich represent @marvelstudios and @therealstanlee," he captioned a picture on Instagram.
Paltrow played Pepper in the "Iron Man" movies, "The Avengers" and "Spider-Man: Homecoming," while Favreau appeared in the "Iron Man" films and "Spider-Man: Homecoming."
Favreau also directed "Iron Man" and "Iron Man 2," and will produce "Avengers: Infinity War."
"Captain America: The Winter Soldier" and "Captain America: Civil War" helmers Anthony and Joe Russo will direct "Avengers: Infinity War."
The movie will see Tony Stark and the Avengers unite with the Guardians of the Galaxy to confront Thanos.
"This is a culmination film ten years in the making and we are pulling the main story threads from all of the different franchises into one unifying narrative," Joe Russo told Screen Rant in July.
"So any of the important characters are going to be in this film and they are going to have something important to do in the movie."
"Avengers: Infinity War" opens in theaters in May 2018.