Police are appealing for the victim of an assault to come forward.
The man was struck on the back with a blunt object after intervening to stop an assault in Berridge Road, Forest Fields.
The assault happened at around 8.25 pm on 13 January this year
Sergeant Mark Southgate, of Nottinghamshire Police, said: “This was a nasty assault against an innocent member of the public that was caught on camera.
“We have identified a suspect from that footage but the victim in this case has not yet come forward.
“This kind of violence is utterly unacceptable and we are determined to get justice for this victim. To do that, however, we would really like to speak with him in person.”
Anyone with further information is asked to call 101 quoting incident 689 of 13 January 2023.