A man had his jaw broken in two places after attending the Rod Stewart concert at the Amex.
The man, from Lee-on-Solent in Hampshire, was attacked at the junction of the A27 and Knights Gale Road as he left the concert at around 10.30pm on June 13.
Another man got out of a BMW car and struck the victim - breaking his jaw and leaving him bleeding from the mouth.
The victim returned home and went to his local hospital the following day where he was admitted and underwent surgery.
His jaw was broken in two places with an additional green stick fracture, requiring a significant number of plates and screws to be inserted.
There is no description of the offender.
Anyone with information should call 101 or email firstname.lastname@example.org quoting serial 980 of 19/06.