The 21-year-old victim was attacked on Aughton Road, close to Aston Academy and Swallownest Court, today.
South Yorkshire Police said officers were called shortly after midday to reports of four males, believed to be aged around 15, attacking another man.
A spokesman for the force said the victim had been punched and kicked and sustained a cut to the back of his head which may have been caused by a broken bottle.
He said the man was taken to hospital to be checked over but his injuries are not believed to be serious.
CID officers are investigating and have conducted house-to-house enquiries but no arrests have yet been made.
Anyone with information is asked to call police on 101, quoting the incident number 349 of August 31.