The importance of MotoGP test riders has been underlined in recent years by the signing of big-name stars such as Casey Stoner (Ducati), Dani Pedrosa (KTM), Jorge Lorenzo (Yamaha) and now Cal Crutchlow (Yamaha).

But it's arguably an even more vital role at reigning world champion's Suzuki which, along with Aprilia, has only two riders on the MotoGP grid.

The Hamamatsu factory places most of its development trust in the hands of former World Superbike champion and 250cc/MotoGP rider Sylvain Guintoli.

The Frenchman, 38, is still fast enough to claim a twelfth-place finish at Silverstone in 2019 - one of ten wild-card/replacement appearances on the GSX-RR over the past four years.

But his sensitivity to bike behaviour is equally impressive, as one mishap by Suzuki proved.

"Sylvain is very important for us to develop the bike, to evaluate the direction. For instance, his comments are always very accurate and his lap time is very close to race riders, considering he's a test rider," said Suzuki MotoGP project leader Shinichi Sahara.

"The funny thing was he tried one electronics test item but accidentally the mapping was not changed before he tried. He didn’t know and he tried it, so I asked him: 'How was the difference?'

"He said: 'No, I cannot feel a difference'. I said 'yeah, you're right!' He is so accurate!

"He's also consistent and physically very strong. But unfortunately last year due to the Covid-19 situation, he couldn't test as much as he wanted."

Guintoli has been making up for lost track time by working though a range of new parts, such as a chassis and swingarm, at the recent Qatar tests - as well as trying an early 2022-spec Suzuki engine.

Also on track at Losail was fellow Suzuki test rider Takuya Tsuda, who is usually responsible for development work in Japan.

"We have another test rider in Japan, Tsuda. He improved his performance as a test rider in Motegi, with a lap time as good as Sylvain and his comments are getting more accurate," said Sahara.

"We have these two good test riders."

Guintoli's best lap of the Losail tests was a 1m 55.642s, which compared with 1m 53.827s for reigning world champion Joan Mir and 1m 53.860s for team-mate Alex Rins. Tsuda's best was a 1m 57.795s.

In addition to his MotoGP testing and wild-card duties, Guintoli will be competing in this year's Endurance World championship for the Yoshimura SERT team.