UPDATE 1:50 PM PT: The Hollywood Reporter, citing its own sources, has word that the Russo Brothers will direct both halves of the two-part "Avengers: Infinity War."
This follows an earlier report from Badass Digest. Similar to that original report, no writers are said to be official according to THR, but "Captain America: The Winter Soldier" screenwriters Christopher Markus and Stephen McFeely are said to be the "likely' choice.
Badass Digest is reporting that "Captain America: The Winter Soldier" directors Joe Russo and Anthony Russo have signed on to direct the two-part "Avengers: Infinity War" film. The rumor comes from an unnamed source who claims to have just today received an email confirming that the Russos have "closed their deal" to direct the films, which are scheduled for release in 2018 and 2019.
In addition to this rumor, the Digest has also been told that Christopher Markus and Stephen McFeely, the writing duo behind the "Captain America" films as well as TV's "Agent Carter," are in talks to pen "Infinity War's" script. Markus and McFeely's next project is 2016's "Captain America: Civil War," which will also be directed by the Russo brothers. The post mentions that "Civil War" is "instrumental in setting up 'Infinity War.'" The report also states that while the two-part Avengers film isn't expected to hit theaters until 2018 and 2019, "Infinity War" is rumored to "shoot back-to-back in 2016 and 2017."
"Avengers: Infinity War Part 1" is scheduled for release on May 4, 2018. "Part 2" is scheduled for May 3, 2019.