Kobayashi will share the #48 Ally Racing-branded Action Express Racing Cadillac DPi-V.R one last time with Mike Rockenfeller and Jimmie Johnson at Road Atlanta, the fourth and final stop on the Michelin Endurance Cup schedule.
The Toyota-contracted driver however is no longer able to juggle his duties for the Japanese manufacturer with a partial IMSA programme with Cadillac, which is set to become a direct competitor of Toyota in the FIA World Endurance Championship next year with its new V-LMDh.
"Unfortunately, this will be my last race with the Cadillac," said Kobayashi. “I’ve been with Action Express for the last two years. I appreciate the team and my teammates Jimmie and Mike.
"I think we worked really hard to win many races. We pushed really hard. Unfortunately, so far, we haven’t won. But, we are looking forward to winning one race. Jimmie Mike, and I will do our best to win this last race. I’m definitely looking forward to it.”
Kobayashi first joined forces with Cadillac for the 2019 Rolex 24 at Daytona, helping Wayne Taylor Racing to win that year's race, and then coming back the following year to successfully defend the title.
He then joined AXR last year upon WTR's switch to Acura machinery and has been a regular fixture of the four races that make up the Michelin Endurance Cup schedule since then, although another win has proved elusive.
Kobayashi previously told Motorsport.com that a return to IMSA in 2023 was unlikely simply because of his expanding Toyota duties, which now also include his role as team principal of the WEC outfit.
Ally Racing stated its two-year Michelin Endurance Cup programme comes to an end this weekend.
It comes following NASCAR legend Johnson's announcement earlier this week that he will be stepping down from full-time competition after two seasons of focusing mostly on IndyCar.
Cadillac has only so far confirmed a two-car IMSA effort in 2023, with AXR and Chip Ganassi Racing running a single V-LMDh apiece, alongside its one-car attack on the WEC with Ganassi.
