It happened in Carrickfergus during a reported disturbance in the town.
Sergeant Allen from Larne PSNI said: “Police received a report of a disturbance in the Glenkeen Drive area at around 7.35 pm.
“Police checked the area, and a male subsequently reported he had been assaulted by another man and had sustained an injury to his hand.
“We are appealing to anyone who was in the Glenkeen Drive area around 7.30 pm and may have witnessed this incident, or who has any information about it to contact police in Larne on the non-emergency number 101, quoting reference number 1247 of 11/12/17.
“Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous and gives people the power to speak up and stop crime.”