Rawaqa was forced to pull out of the 30-man Fiji squad at the weekend with a prolapsed disc in his back, with the 23-year-old Lautoka player devastated by his cruel injury luck.
"Ifereimi is absolutely shattered and we and the team share his sadness," said coach Mac McCallion.
"There has been a lot of tears shed in camp today."
Fiji Rugby Union (FRU) Chief Executive, Pio Bosco Tikoisuva, has now written to former Test captain Raiwalui in an attempt to get the former Newport and Sale Sharks man to come to the rescue of the team by making himself available for the competition.
The 29-year-old Raiwalui however is one of a number of Pacific players to have made themselves unavailable for the World Cup so that they can stay with their European clubs, but Fiji insist that their last-minute plea to him is by no means a publicity stunt or a set-up.
"This is not a put-on. We need his help now more than ever," said Tikoisuva.
"We had made plans without Simon based on what he told us [about retiring from Test rugby] but we hope he understands the emergency we are facing."
Whether or not Raiwalui decides to go, the absence of Rawaqa is a blow for the Fijians, having been a central figure in the Lautoka side, capturing the Telecom Fiji Cup and Colonial-sponsored Farebrother-Sullivan Challenge Trophy.
"He is a great player with skill and heart in equal measure," said McCallion.
Fiji face a pool campaign against France, Scotland, USA and Japan in the Rugby World Cup, opening up with a tester against France in Brisbane on October 11.
By Mark Smith