Ben Ryan, the coach who guided Fiji's Olympic Sevens team to gold, will join up with the islanders' 15-a-side squad in London in a bid to plot England's downfall when the sides meet at Twickenham on Saturday.
The 45-year-old former England Sevens coach returned to London in August after a three-year stint in charge of Fiji.
Now on the lookout for a coaching role in the 15-a-side game, Ryan has been invited into camp by Fiji coach John McKee where he will be reunited with former charges Leone Nakarawa and Vatemo Ravouvou, who have switched from the Sevens circuit since the Olympic triumph.
"We've worked together in the past," McKee said. "I attended some of the Sevens training sessions and was able to give some pointers and observations and I'm sure Ben will be able to do the same.
"It's always good as a coach to have someone from the outside looking in. You can get tied up in the nitty gritty and that's not always healthy."
The Olympic gold medal, McKee said, "He has given inspiration to Fiji rugby players across the board, to know what can be achieved when the preparation is right. Now they have the confidence to perform on the big stage."