The team later confirmed it had released King.
The Vikings signed King as a rookie free agent last year. He spent most of the season on the practice squad and didn't appear in game action.
King, 24, is accused of assaulting a 22-year-old man at an April 28 birthday party in suburban Minneapolis. King attacked the man, punching him repeatedly and throwing his head into the ground after the man teased him about resembling a celebrity, police said.
The man was hospitalized with skull and facial fractures, as well as with cuts that required more than 50 stitches to close.
Authorities said King has denied assaulting the man and told detectives the man fell to the ground when he was talking to him.
King hasn't been charged and was released from jail Tuesday. Anoka County prosecutors' spokesman David Cossi told The Associated Press that the case remains under investigation.
King's attorney, Lee R. Wolfgram, said his client doesn't have a violent history. "In fact, showed great restraint in attempting to calm a situation after an offensive racial remark was directed at him," Wolfgram said in a statement given to NFL Network insider Jason La Canfora.
King, a highly touted recruit who ran into several problems during his college career at Georgia, once was arrested for failing to appear for a court date on a speeding ticket. He was declared academically ineligible in his final year of college and went undrafted in the NFL supplemental draft before signing with the Vikings.
The Associated Press contributed to this report.