The character is shown wearing a baseball cap, headphones, jacket and longpants and carrying an assault rifle, reported Aceshowbiz.
While Ayer did not provide any details on the picture, fans guessed that the character was Deathstroke.
Deathstroke has been rumoured for several months to appear in the DC villain flick with one report claiming that the character was the one being played by Jim Parrack.
Back in December, a report suggested that Deathstroke would be the bodyguard of Amanda Waller (Viola Davis).
The baseball cap and the headphones, however, would not go well with the character's famed orange and black mask.
"Suicide Squad" starring Will Smith, Jared Leto, Margot Robbie, Joel Kinnaman and Cara Delevingne will hit theatres in the US on August 5, 2016.