The 32-year-old man was found with serious head injuriesÂ in Dyche Lane, Jordanthorpe,Â at 3am on Saturday.Â
Paramedics alerted South Yorkshire Police to the man'sÂ condition and an investigation was launched.
POLICE: Weapons,Â drugs, stolen vehicles and cash found during police raids on Sheffield estate Detectives are trying to establish how the man sustained his injuries.
A police cordon was put in place where the man was found while officers examined the potential crime scene.
The casualty was taken toÂ the Northern General Hospital, before being transferred to theÂ Royal Hallamshire Hospital's head trauma unit, where he remained last night.
Anyone with information as to what happened should call South Yorkshire police on 101 and quoteÂ incident number 135 of October 27.Â