Lancashire Police are investigating an incident in Blackpool which left Lincoln City defender Kern Miller with his jaw broken in two places.
Miller, 19, was taken to hospital after being found at a taxi rank in the early hours of 12 December before being moved to Preston for surgery.
It is not known if he was assaulted or if the injury was caused by a fall.
A police statement said: "It is still unclear how he came about his injuries and CCTV enquiries are under way."
It is understood that Miller was on a night out with friends in Blackpool when the incident occurred.
Lincoln chairman Bob Dorrian told BBC Lincolnshire that the club would carry out its own enquiry.
He said: "Kern's out of hospital now and when he's in a position to explain to us what happened we'll take it from there.
"As a club we take our responsibilities very seriously and we will investigate the matter."
Miller, who signed his first professional contract with the Imps in June, came through the youth ranks at Sincil Bank but has made only one first-team appearance, as a sub against Accrington in April 2009.