Rossi, who tested Ferrari F1 cars last decade, collided with reigning world champion Marquez during last weekend’s Malaysian Grand Prix, and will start the Valencia finale from the back of the grid.

It heightened a row between the pair that had erupted days earlier, when Rossi accused Marquez of “thinking like a child” and aiming to help countryman Jorge Lorenzo win the title.

“I think he still has the chance, he’s a fighter, it’s in his nature,” Vettel said when asked about Rossi.

“Even if after the [Malaysian] race it sounded like he was giving up, he will be fighting and giving everything he has and I think he did the absolute right thing in Malaysia.

“I know Jorge as well and Marc a little bit, and they are very good guys but Valentino did the right thing.”