With Takaaki Nakagami promoted to the latest Honda machinery, the only MotoGP riders on 'year-old' bikes this season will be Petronas Yamaha's Franco Morbidelli and Avintia Ducati rookies Enea Bastianini and Luca Marini.

Like Yamaha, despite the engine development freeze, Ducati is keeping the same machinery format as last season.

That means the Official Team (Jack Miller and Francesco Bagnaia) plus Pramac (Johann Zarco and Jorge Martin) running the 'latest' GP20-based Desmosedicis, while Bastianini and Marini use GP19-based bikes.

Engines must remain unchanged from last season, it is possible to make chassis, electronics and aerodynamic updates for all bike specifications.

While Zarco had expressed serious doubts before joining Avintia, he went on to make history for the team by claiming a pole position, podium and fastest lap on the GP19.

Valentino Rossi believes the combination of riders, team and bikes is good enough for younger brother Marini and newly crowned Moto2 champion Bastianini to aim for competitive results in their rookie season.

"Marini and Bastianini did fantastic things with the Moto2, fighting for the championship until the last race. In MotoGP they will have a very good bike, the Ducati, and a good team. So I think that also for Marini and Bastianini already they can competitive in 2021," Rossi said.

The Italian also credited the Moto2 class as a good training ground for the 'very strong' riders now forming the 'new generation' in MotoGP, headlined by Suzuki's 2020 champion Joan Mir.

Both Bastianini and Marini took three Moto2 wins last season, Bastianini clinching the crown by just nine points over Marini (tied with Sam Lowes) after a final round showdown in Portimao.

Martin (two wins) was also in title contention until being forced to miss both Misano rounds due to a positive Covid test, eventually finishing fifth.

"Practically all the young riders that arrive in MotoGP from Moto2 in the last years are very competitive," Rossi said.

"The list is very long of people that fight for the championship in Moto2 [but] they are usually fast with the MotoGP bike from the first moment.

"It looks likes the Moto2 category is a good school and there are a lot of very strong riders in this 'new generation', like we saw with Mir."

Since replacing 250cc in 2010, the Moto2 class has been won by; Toni Elias, Stefan Bradl, Marc Marquez, Pol Espargaro, Tito Rabat, Johann Zarco (twice), Franco Morbidelli, Francesco Bagnaia, Alex Marquez and now Bastianini.

There are rumours that Rossi's VR46 team, which will help run Marini within the Avintia structure this season, will take over both grid slots for 2022.