Police have released photographs of men they want to trace after a shop assistant was attacked as he challenged thieves.
A group of men assaulted a member of staff from Steers Beers, Burngreave Road, Burngreave, after he confronted them for stealing alcohol.
The shop assistant was attacked close to the junction with Cranworth Road after he left the shop.
He suffered a serious shoulder injury but has since been discharged from hospital.
Police believe the men in the CCTV images could hold vital information about the incident at 1.15pm on Friday, May 13.