The Japanese manufacturer took the covers off the forerunner of what will be its first entry into the GT3 marketplace in almost a decade at last year's Tokyo Auto Salon, with ambitions of taking it to the World Endurance Championship and Le Mans 24 Hours.
Since then, the car is known to have started track testing, and was spotted in action during a private test session at Toyota-owned Fuji Speedway earlier this year.
It had been thought that the car was being lined up for a race debut in 2025, the year after the WEC is opened up to GT3 cars.
But due to delays to the planned release of the GR GT3-derived road car that will be launched to coincide with the race version, Toyota is now targeting a WEC debut in 2026.
"Everybody knows we are developing a car, and this car will come to race in Europe in 2026," Toyota WEC team director Rob Leupen told Autosport.
"The date is in alignment with the road car side, which is following the philosophy of Toyota to have a motorsport-bred car on the road. This is moving forward at the moment."
Reports have suggested that the car based on the GR GT3 will be badged as a Lexus, which has repeatedly hinted at introducing a successor for the ageing RC F GT3.
Asked whether the new car will be known as a Lexus, Leupen replied: "At the moment, it seems to be. It depends on how it develops within Toyota, but at the moment, yes."
Leupen wouldn't be drawn on whether the new car would be given a race debut before it comes to the WEC in 2026.
Racing the car in an unhomologated state in Japan's Super Taikyu series would be an option should Toyota wish to gain race mileage with the car before its official debut.
Toyota should in theory be guaranteed grid slots for the GR GT3-derived racer in 2026, as the WEC has clarified that existing Hypercar manufacturers will be given priority when it comes to allocating places.
It was revealed in the run-up to Le Mans earlier this month that manufacturers will be offered no fewer and no more than two entries each.