The Swede will pilot the #83 Red Bull Toyota for a second time this year, having made his NASCAR debut in June. Ekstrom drove in the first road course event of the season at Infineon Raceway, where he finished 21st after starting 38th, leading the race for seven laps.
After racing in the DTM last weekend at Brands Hatch, the 32-year-old tested for Red Bull on an oval for the first time on Tuesday at the North Wilkesboro Speedway, a 0.625 oval in North Carolina, where he successfully completed his preparation to compete next Saturday in the final race of the regular season at the 0.75-mile Richmond International Raceway.
"To do a race on an oval is something different - it's a lot of laps and a lot of cars," said Ekstrom. "Racing in Richmond will be one of the biggest tasks of my life so far, but I feel I am ready for the challenge."
Ekstrom replaces Reed Sorenson, who has driven the #83 car for eighth of the past nine races. Brian Vickers started his fourth year at the wheel of the leading Red Bull entry but he has been sidelined from racing since May after being diagnosed with blood clots. Casey Mears, Boris Said and Ekstrom, have also driven the car this year.
"Mattias did a great job in Sonoma, and continues to impress at the oval track testing sessions," said Red Bull Racing Team's Jay Frye. "He has earned this opportunity, showing continued improvement every time he is behind the wheel."
Ekstrom is expected to be back behind the wheel of his DTM Audi A4 next week, when the series competes at Oschersleben. With four events remaining, he ranks fifth in the DTM standings.
Henrique returns to RacingEkstrom open-minded for Sears Point