The 6ft 8in giant striker nearly joined the Hammers in January, but Traore opted to join Everton on loan instead after he passed a work permit appeal hearing arranged by West Ham and led by Sam Allardyce and club secretary Andy Pincher.
He scored on his debut for Everton against Swansea in the FA Cup in February but sustained a hamstring injury six days later in a warm-up ahead a game with Chelsea and missed the rest of the season. West Ham could look at a potential loan deal again.