Is Scott Eastwood playing Dick Grayson aka Nightwing? That's the most popular rumor, which further states that Ben Affleck's Batman sends Grayson undercover to find out what Amanda Waller (Viola Davis) is planning. However, there's also rumors that Eastwood is playing a descendant of Chris Pine's Steve Trevor, who's a key character in Wonder Woman, which is set during World War I. In yet another rumor (from last Summer), Heroic Hollywood stated that Eastwood was playing Slade Wilson aka Deathstroke.
With all the rumors floating around out there, it's important to remember that fans that love a certain amount of speculation have been burned before by the DCEU. After months and months of wild theories, it turned out Jena Malone was playing an obscure S.T.A.R. Labs scientist in Batman v Superman. Dan Amboyer, who was rumored to be playing Hal Jordan, turned out to be a Drone Pilot (who I'm still unsure on whether he actually appears in the film). However, what sets Eastwood apart from Malone and Amboyer is the fact that he's actually appeared in the film's promotional material which gives away the fact that he works rather closely with Joel Kinnaman's Rick Flag and Task Force X.
Perhaps you should temper those expectations before you're burned yet again. According to a German film site [via DCMovies.com], Eastwood is playing Lieutenant “GQ” Edwards and Barinholz is playing Captain Griggs. There's no DC Comics character by the name of GQ Edwards but Captain Griggs is a character with ties to Wonder Woman, Etta Candy and Steve Trevor.
As always, keep this one labeled as a rumor for now, but it's certainly more plausible than some of the previous theories that have been bandied about.
Suicide Squad arrives in theaters on August 05, 2016.