A man remains in hospital today in a serious condition after the incident which happened near a town centre pub, believe police who are still investigating.
Police tape was sealing off Orchard Street, a narrow road which runs alongside the Orchard Square shopping centre, and runs between Leopold Street and Church Street.
A marked police patrol car and an uniformed police officer were in place guarding the scene this afternoon.
A red mark could be seen on the ground, which looked like blood.
South Yorkshire Police issued a statement this afternoon about the incident.
They said: “Police were called to Orchard Street, Sheffield, at 11.18pm last night (Thursday 23 December) to reports of a man aged in his 50s having been assaulted.
“The man was taken to hospital where he remains in a serious condition.
“It is thought the incident happened outside Woody’s Bar.
“Enquiries into the incident remain ongoing.”
Any witnesses are asked to call police on 101 quoting incident number 987 of 23 December or use the force’s online reporting portal, by logging onto https://www.southyorks.police.uk/contact-us/report-something/
Two people who saw the aftermath of the incident last night told The Star that they had seen a man on the floor last night after the suspected incident, at around 11.30pm.
They said they had seen an ambulance and police at the scene.
"People were shocked to see what had happened,” said one.