Paris - Dutch Superbike rider Michael van der Mark will stand in for injured star Valentino Rossi at the Aragon MotoGP later this month, Yamaha announced on Monday.
Nine-time world champion Rossi is recovering from a broken leg sustained in a training accident last month.
The 38-year-old missed Sunday's race in San Marino, and will be absent again in Aragon on September 24 with a forecast return to action in Japan in October.
Van der Mark, who has experience in the former 125cc class and in Moto2, will be making his MotoGP debut without any prior testing.
"I've never ridden a MotoGP bike before, so this will be a completely new experience for me," the 24-year-old said in a statement released by Yamaha.
Yamaha Motor Racing managing director Lin Jarvis commented: "It is never easy to step in to replace another rider and even more difficult to replace Valentino Rossi.
"But we believe that Michael has all the credentials and experience to do a good job."
He teams up with Yamaha's Maverick Vinales, third in the championship standings after a fourth place finish to Marc Marquez in San Marino.
Jarvis added: "We also hope that Valentino will continue to make a rapid recovery and that we will see him again, back on his YZR-M1, on the earliest possible occasion."
Van der Mark is due to become the first Dutch MotoGP rider since Jurgen van den Goorbergh in 2005.