Oakland Raiders receiver Darrius Heyward-Bey was briefly knocked unconscious after colliding with Pittsburgh Steelers safety Ryan Mundy during Sunday's game in Oakland.
It happened in the fourth quarter as Mundy came over to break up a pass to Heyward-Bey in the end zone. Heyward-Bey was unable to catch the pass, and Mundy appeared to hit Heyward-Bey in the chin with his helmet. Although Heyward-Bey was defenseless, no penalty was called on the play by the replacement officials.
Heyward-Bey was unconscious for a few minutes, but did appear to regain consciousness while being carted off the field, as he was communicating with the medical staff and gave the crowd a "thumbs-up" sign.
Video via G4SportsNews. H/T Business Insider.