Pirelli chairman Marco Tronchetti Provera has reiterated his call for Mercedes and Red Bull to put their “best” drivers in the car for the 2017 tyre tests.
Mercedes, along with Ferrari and Red Bull Racing, have taken on the responsibility of helping Pirelli prepare for next season.
However, to date only Ferrari have used their race drivers, Sebastian Vettel and Kimi Raikkonen, to test the new wider tyres.
Mercedes ran Manor driver Pascal Wehrlein at Paul Ricard while Red Bull used test driver Sebastien Buemi when they were in action at Mugello.
Tronchetti Provera, though, hopes the likes of Lewis Hamilton and Nico Rosberg will soon be testing.
He told Autosport: “It’s wrong for them if they don’t.
“Ferrari gave the best drivers and I think and hope all the rest will give them.
“The priority is to have the best pilot.
“The speed is changing, so the best pilots, they have to test it. They have the sensibility to understand the change [in the tyres].”
As for Nico Rosberg saying he will wait until it is “really useful”, Tronchetti Provera added: “It’s up to them, it’s not yet in the agenda. I hope to see on the agenda, also their names.”