Jorge Lorenzo's return to Yamaha this season made the five-time world champion the most highly qualified test rider of the MotoGP era.

But so far he's only taken part in two tests, at Sepang in February and then - after disruption caused by the Covid pandemic, which also erased his Catalunya wild-card - this week in Portimao. Both were on the 2019-spec M1.

While Lorenzo was only 1.3s from fastest man Fabio Quartararo (Yamaha) at Sepang, the gap had grown to 3.0s behind Aleix Espargaro (Aprilia) at Portimao.

It would have been even bigger if race riders other than Aprilia had been able to use MotoGP machines (rather than street bikes) and had been on track for both days.

Lorenzo, who believes 15-16 days of Yamaha testing were planned before the Covid outbreak, has indicated he would like to continue in the role for 2021.

Former team-mate and title rival Valentino Rossi feels Lorenzo has 'big potential' as a test rider, but needs to ride a lot more.

"Jorge in Malaysia in February was not so bad. Because he did a good job and he was strong with the M1. He was close to us, to the normal riders," Rossi said. "But after, he said that he never rode a bike until Portimao.

"So I think that Jorge is a great opportunity for Yamaha because he has a big potential, but if you want to be the test rider he needs to train, to use motorcycles.

"Because if you stay eight months without touching a motorcycle, after it's impossible to bring a MotoGP bike to the limit. So I think if Jorge wants to continue, he needs to test and to ride some other type of motorcycle during the season."

Speaking at Le Mans on Saturday, Rossi also addressed the ongoing rumours of whether VR46 is in talks to take over Avintia's MotoGP grid places.

The Italian again said that the discussions currently taking place between VR46, Avintia and Ducati are only about finding a MotoGP seat for his brother Luca Marini, who could replace the struggling Tito Rabat next season.

"We are interested for Luca, to bring Luca into MotoGP next year. For that reason. But they are still speaking. I don’t know if it will be possible. I hope to have Luca in MotoGP," Rossi said.

2022 would be a more logical time for VR46 to enter MotoGP as a team, since they would not need to purchase any existing grid places, which are currently contracted until the end of 2021.

Of more immediate concern to Rossi is Sunday's French MotoGP, which he will start from just tenth on the grid, but having earlier completed an all-Yamaha top four for race pace in final practice.

"I'm not happy about my tenth position because I have to do better, because our potential is better," he said. "So when you start from tenth, in the modern MotoGP you never know where you can arrive.

"But we have to work this evening because we have something to fix, because the bike in acceleration is a bit too nervous.

"So we need to improve this. And after my pace is good. I am quite strong. So the race is long, you need to start well and try the maximum for the 27 laps and try to understand where I can arrive."