Reigning MotoGP champion and runaway title leader Marc Marquez has backed struggling team-mate Jorge Lorenzo to remain at Repsol Honda next season.

Jack Miller now believes there is 'some truth' to rumours Lorenzo is pondering a 2020 Ducati return via the Australian's Pramac seat, following a torrid, injury-littered start to his Honda career.

However, Marquez doubts Lorenzo, a triple MotoGP champion with Yamaha and then triple race winner for Ducati, will be prepared to throw in the towel early at HRC.

"All I only know is that Jorge has one more year's contract with Honda," Marquez said.

"Jorge is Jorge and what he says is 'he's not [just] a great rider, he's a champion' and if he's a champion, he is on a champion bike and he needs to come back and show his potential with the Honda bike and be in the top with the Honda bike.

"And I think with his ego and his ambition he will try to do, because if not his dream will not arrive. I mean, when you arrive in a project like HRC, it's because you want to win races and fight for the championships."

"I completely agree with Marc," added Lorenzo's former Ducati team-mate Andrea Dovizioso.