The 28-year-old man from York was attacked by a member of the opposing team during a match at York Sports Village in Heslington sometime after 9.20pm on Tuesday September 29.
The offender is described as a white man, aged early to mid-twenties with short shaven hair and of stocky build. He was wearing a red Liverpool football kit.
Anyone who witnessed the incident is asked to contact North Yorkshire Police.
Dial 101, press 2 and ask to speak to PC Adrienne McCoubrey or email [email protected]