The officer has been relieved of his duties pending an investigation by the city's Civilian Office of Police Accountability, according to the Chicago Police Department.
Jovonna Jamison, who recorded the video, told ABC News in an interview Friday that she was "shocked" when she saw the officer pick the man up.
"I was praying and hoping he was alive cause he wasn’t moving," Jamison said.
Police said in a statement the man was drinking in public, which prompted them to approach him.
However, according to police, he became "irate" and licked the officer's face before spitting in his eye and mouth.
"The officer then performed an emergency takedown, taking the offender to the ground," according to the statement.
Jamison said she did not see him resist in any way.
"That gentleman didn’t do anything wrong," she said.