Austin Dillon will stand in for the injured Tony Stewart in this weekend's NASCAR Sprint Cup race at Michigan International Speedway.
Stewart has been sidelined with a broken leg following a sprint car accident at Southern Iowa Speedway last week.
Dillon currently leads the Nationwide Series standings for Richard Childress Racing.
Grandson of legendary team owner Richard Childress, the 23-year-old was Truck Series champion in 2011 and has made a handful of Cup starts with RCR and Phoenix Racing.
Stewart was released from hospital on Sunday. There is not yet any indication when he will be fit to return to racing for his Stewart-Haas team.
"I've watched Austin for many years and at each stage of his racing career he's been successful," Stewart said.
"He's proven to be a very fast learner, and he's able to adapt quickly. Being the youngest champion in the history of the Truck Series is proof of that.
"His background in dirt racing is an asset, and off the track we share many of the same interests, specifically, hunting and fishing."
In his absence, Stewart dropped to 17th in the standings and out of the provisional Chase spots following last Sunday's Watkins Glen race.
Max Papis substituted for him in that event, finishing 15th.