Factory Yamaha riders Maverick Vinales and Valentino Rossi have expressed concern after Franco Morbidelli's M1 engine let go in today's Jerez MotoGP exactly a week after The Doctor's did the same thing at the same track.

Morbidelli was forced off track with nine laps left to run in Andalucia and Vinales revealed that he also had an engine issue in third practice yesterday.

"I had a strange noise from the bike so I stop in the garage but I know nothing more," said Vinales.

"The engine didn't give any problem right now and in the race was consistent, didn't drop the power in the race so we will see.

"They have now two weeks to understand what was the problem on the engine. We see Franco broke and engine, Valentino broke an engine last week so we need to find and fix it.

"It's very important as this championship is difficult and we have to put a lot of pressure on the engines, especially in the next two races."

Rossi added: "I don't know the problem of Franco. My engineer see the problem of last week and they try to understand and fix. For sure we have to pay attention because we close the engine for a longer time but I hope Yamaha fix the problem."

Conversely, double winner and championship leader Fabio Quartararo says he isn't worried but he is also the newest rider to the manufacturer and is probably more concerned about saying the wrong thing.

"I am not worried. My job as a rider is to perform on the track and there are hundreds of engineers working on the bike and if there is a problem, we have two weeks to find something. I have had xero problems with the engine and I am focused on riding."