Pirro, who will perform a new role as track analyst for Jorge Lorenzo in 2017, has also been in charge of the development of Ducati's Desmosedici machine in recent years.

Last season, the Italian shared the track with Stoner in some test sessions, as Ducati wanted to learn the former world champion’s opinion on different aspects of its prototype.

Pirro concluded Stoner is a truly unique rider, as the Italian tester recognises he could never match Stoner’s lap times, despite the Australian being retired since the end of the 2012 season.

The first MotoGP official test in 2017, held last week in Malaysia, saw the Southport rider finish the first day on top of the timesheets with a lap time of 1m59.6s. He set an identical time on Wednesday, the last day of the test.

These similar lap times validate Pirro’s thesis; he believes Stoner's strong point is to be able to find the limit of the bike earlier than anyone else.

“Casey has the ability to take a very short time to find the limit of the bike. He gets it before any other rider," Pirro told Motorsport.com.

"Jorge also finds it, but he uses a different method; Stoner does not need a long time. Then, both riders are fast, but Casey's way is just incredible.

"I think that’s a unique ability, despite not having raced at all, he manages to find the limit."

He added: “The first day at Sepang he did a 1m59.6s, and the last one he matched that lap time again. The limit was there, but he was able to find it already on Monday."

Pirro set his fastest lap time of the test on Tuesday with a 2m01.3s, a full 1.7s behind Stoner.