Three-time NASCAR champion Tony Stewart is expected to announce later this week that he will retire following the 2016 Sprint Cup season.
Reports are circling in the United States that Stewart will step down from full-time driving, handing his seat to Clint Bowyer.
Bowyer is currently without a confirmed ride beyond the end of the current season due to the impending closure of Michael Waltrip Racing.
The experienced campaigner is likely to be placed in a customer Chevrolet outfit next year before stepping up to Stewart-Haas Racing.
Stewart has competed full-time in the premier NASCAR division since 1999, spending 10 season with Joe Gibbs Racing before starting his own team with Gene Haas.
Taking the most recent of his three titles in 2011, Stewart has not won a race since midway through 2013.
The 44-year-old missed the end of that season after breaking his leg in a sprintcar crash, before also missing races last year following his involvement in a speedway accident that killed Kevin Ward Jr.
Although cleared of any charges by a New York grand jury following the tragedy, a wrongful death lawsuit filed by Ward's family is yet to be heard.
Stewart is just 26th in this year's Sprint Cup standings having failed to make the Chase for the second straight season.