Around 6.30pm on Thursday 15 October, the 16-year-old victim was with a group of friends when he was approached by two unknown men.
One of them assaulted him and stole his gold ring, while the other stole his trainers before returning them a short while later.
Following this, the suspects ordered one of the other youths to hit the victim in the face several times, threatening violence if they failed to do so.
One suspect was white with dark blond hair, wearing grey tracksuit bottoms, a grey jumper and black trainers; the other was white, with a small pony tail, wearing a black puffer jacket with a fur lined hood, a grey tracksuit top and grey tracksuit bottoms.
They are believed to have made off in the direction of Haywards Heath railway station.
A 21-year-old man from Chichester, arrested on suspicion of robbery, has been released on conditional bail until 15 November, pending further investigation.
A 24-year-old man from Haywards Heath, arrested on suspicion of robbery, has been released on conditional bail until 13 November, pending further investigation.
Anyone with any information about the incident is urged to report it online or call 101, quoting serial 1141 of 15/11.