Super Formula champion Kunimoto in Toyota Le Mans frame

The Japanese driver has already driven the TS050 Hybrid in Spain twice this year alongside fellow countryman Ryo Hirakawa, who is widely expected to get one of the two vacant seats in the car.

So far, Toyota has only confirmed Stephane Sarrazin – who was demoted from the squad’s full-time line-up to make way for Jose Maria Lopez – in its #9 entry, which will also race in the WEC 6 Hours of Spa.

Motorsport.com understands that Toyota has used last week’s latest test to evaluate Kunimoto ahead of taking a final decision on its line-up.

The 26-year-old beat Porsche WEC signing Andre Lotterer to last year’s Super Formula title, and has also been a race winner on two occasions for Toyota brand Lexus in Super GT.

He is set to continue racing in both series in 2017, although the Autopolis Super GT round clashes with the WEC event at Spa.

Audi factory driver Lucas di Grassi was regarded as another possible option for Toyota’s third Le Mans entry, after the Brazilian stated it's "highly likely" he'll be back at La Sarthe this year.

However, the former Audi LMP1 driver is believed now to be out of the picture and is likely to instead pursue a GTE Pro drive for the event.

Additional reporting by Kunihiko Akai