Colin McRae will make a world rally comeback in Turkey as replacement for injured champion Sebastien Loeb.
McRae was Britain's first world rally champion
Kronos Citroen driver Loeb, on the verge of a third straight WRC title, broke his arm in a cycling accident and misses the 13-15 October event.
According to French newspaper L'Equipe, Loeb says he is unsure when he will be able to return to action.
McRae, the 1995 world champion, was Loeb's team-mate at Citroen in 2003 but lost his drive at the end of that year.
The 38-year-old Scot's last WRC appearance came at the end of 2005 with Skoda, when he competed in two events.
McRae will be partnered by long-time co-driver Nicky Grist of Wales.
The pair parted company in 2002 after several successful seasons together, with McRae saying their relationship had become "strained".
When you drive in rallies all year, you don't imagine that you can put your career at risk by riding a bike
A statement from Kronos said: "(Team boss) Marc van Dalen and (Citroen Sport director) Guy Frequelin have searched for the best solution to help the team defend its lead in both the drivers' and manufacturers' championships.
"Colin McRae has been chosen to help the team, and he is highly motivated to do his maximum to serve Sebastien and Kronos Citroen's interests."
Frenchman Loeb, who has a 35-point advantage over Finland's Marcus Gronholm with four races left this season, has backed McRae's appointment.
"Of all the drivers who were available, Colin is the one who has the best record, the greatest experience and who's also probably the fastest," said Loeb said.
"Another important trump card is that he knows the car well."
Loeb damaged his arm after falling off his mountain bike during training but still hopes to claim the championship title.
"As long as I won't be there, it will be easier for Marcus to win rallies," said Loeb.
"That said, if he has the slightest problem, he could be out of it without me having to get involved.
"How soon I will return will depend on how it all develops and for the moment, it's impossible to say.
"When you drive in rallies all year, you don't imagine that you can put your career at risk by riding a bike, but that's part of my physical preparation."