The 32-year-old actor recently injured his hand while hitting the mirror as part of a scene in his new film 'Nightcrawler', reported E!Online.
The actor made his appearance during the 2013 Variety Screening of his previous movie 'Prisoners in Hollywood'.
Gyllenhaal donned a tight-fitting black suit and posed for pictures with his costar Maria Bello. His nude colored bandage, which could have easily gone unnoticed, was wrapped around his left wrist.
"Jake was indeed filming 'Nightcrawler' when during the shooting of an intense scene his character purposefully banged his hand into the mirror," his representative said.
