Ex-Formula 1 driver Kamui Kobayashi will test for the Toyota Racing team at Spa on Tuesday as the team validates its Le Mans package for the official test day.
The Japanese manufacturer has returned to the scene of its uncompetitive showing at the second WEC round earlier this month, with both Kobayashi and Mike Conway on driving duties.
Kobayashi is getting more seat time in the car in preparation for the possibility of being called upon to replace the recovering Kazuki Nakajima.
However, Motorsport.com understands that Nakajima is highly likely to be fit enough to compete at both the test day and at the race week itself.
The reigning world champion team is using two days of running at Spa for essential validation and systems checks before heading to Le Mans.
Toyota has had a tough start to the season, with relatively uncompetitive performances at both Silverstone and Spa.
The team has also suffered on-track incidents, not only with Nakajima's accident at Spa but also with two chassis-damaging offs at the official Paul Ricard test in March and one in at an endurance test in mid-April.
There has been an overriding feeling in the paddock that Toyota has chosen a strict conservative approach to 2015 in order to ensure the best possible chance of winning the Le Mans 24 hours for the first time.
Last year meant bitter disappointment when Nakajima, Alex Wurz and Stephane Sarrazin opened up a two-minute lead only to retire in the 14th hour with an electrical connector problem.
After taking the 2014 WEC title, Toyota management focused the majority of their combined efforts on challenging for a first Le Mans victory.
The performance gains from Toyota since last season have not been as impressive as their direct German opponents at Audi and Porsche.
However, the strength of the Toyota TS 040 HYBRID at high-speed braking points such as Mulsanne Corner and Indianapolis and the subsequent acceleration from the two-pronged MGU-K 'push' from the front-axle and rear systems could allow them to reduce the deficit on the 8.4 mile Circuit de la Sarthe.
Toyota will certainly be hoping that its low-drag aero-kit and the reduced altitude of Le Mans compared to Spa, which had an effect on the 3.7-litre normally aspirated V8 engine, will put it back in the hunt at La Sarthe.