The incident happened at around 6.30pm on Thursday 6 September in Noel Street, Hyson Green.
A man aged between 30 and 35-years-old approached the boy and his mother.
Nottinghamshire Police have released a CCTV image of a man they want to speak to in connection with the incident.
More top news
Northampton star Dylan Hartley has been dropped from England's World Cup squad and replaced by the player he headbutted during a game.
May has been unseasonably cool and wet, especially the first half, with more rain today. Summer starts on Monday will it bring the heat?
A man's arm was nearly severed off in a "ferocious and violent" machete attack involving around eight men, police said.