The image was taken in the back of a Sanford, Fla. police cruiser on the night Zimmerman got into a struggle with 17-year-old Trayvon Martin, who he later fatally shot.
Zimmerman's lawyers contend that the neighborhood watchman was appropriately defending himself against the hostile teen. Martin's family and the prosecution, however, claim that Zimmerman's actions amount to murder.
While Zimmerman's defense team feels that the photos show evidence of a violent struggle between the two men, they're proceeding with caution.
"It's not a game changer," Zimmerman lawyer Mark O'Mara told Reuters.
Ben Crump, attorney for the Martin family, believes the photo adds nothing new to the case, as the prosecution had previously released evidence detailing wounds to Zimmerman's nose.
"Trayvon Martin was defending himself. He had every right to stand his ground to defend himself," Crump said.
O'Mara says he received a grainier copy of the image in May, though he's demanded a higher resolution image since then. He posted the new photo to Zimmerman's defense website Monday.
Zimmerman's murder trial is set for June 2013.