Oldham Athletic midfielder Hallam Hope was left with “serious injuries” after being “viciously assaulted” outside Boundary Park following their National League match against Chesterfield.
The club said the incident happened in the staff car park on Saturday.
The 28-year-old required hospital treatment and will be out “for some weeks”, a club statement added.
The Latics said the matter had been reported to the police and they had provided CCTV footage of the incident.
“The club is supporting Hallam and will continue to do so. We wish him a speedy recovery from a dreadful experience,” an Oldham Athletic statement said.
“Whilst the investigation is continuing Oldham Athletic will make no further comment on the incident.”
Hope played all 90 minutes of Saturday’s 2-0 defeat by Chesterfield.
After joining Oldham in 2021, he remained with the club following their relegation from League Two last season and has scored three goals in seven league appearances this term.