Jonas Folger says it was his decision to 'cancel' any further stand-in appearances for the Petronas Moto2 team, as he nears ' fundamental decisions about my career as a racer'.

After withdrawing from the Tech3 Yamaha MotoGP team due to severe fatigue at the end of 2017, Folger sat out last season before returning to Moto2 action for five rounds with Petronas, alongside work as a factory Yamaha test rider.

The German now has his sights set on a full-time Moto2 return in 2020, something that is unlikely to be compatible with the Yamaha test job. The decision not to continue the Petronas also suggests Folger will not be part of their Moto2 plans next year, when the Sepang team is aiming to run a second machine.

"After long consideration I decided after the race in Spielberg that I’ll not to continue with the Petronas team anymore," said Folger, who led opening practice for his home Sachsenring round, but was unable to qualify inside the top 20 and had a best race finish of 17th during his Petronas appearances.

"I’ve to make some fundamental decisions about my career as a racer soon. That's why I've cancelled Petronas for further races. It was my own will. Nevertheless, I want to thank Johan Stigefelt and the whole team for everything. Above all, that I was their first choice when it came to find a replacement for Khairul.

"The last five races have been a great opportunity for me. I was able to start racing again without pressure. So, I got a detailed assessment of my condition. Furthermore, it was a lot of fun to work with my former crew again. That was certainly a decisive factor on my part for this temporary comeback.

"Therefore, once again a big thank you to the Petronas team and I wish them all the best and lots of success for the future and that Khairul will be soon completely healthy again."

Mattia Pasini replaced the injured Khairul Idham Pawi at Le Mans and Mugello. Folger then took over when the Italian was injured in a motocross accident.

Bradley Smith will be on the Sepang team's Kalex chassis at Silverstone, with Folger currently testing for Yamaha in Finland.

Should Folger commit to Moto2 full-time next season, and be unable to continue as Yamaha's European test rider, it might offer an opportunity for Johann Zarco. However, the Frenchman is also thought to be considering Moto2 in 2020 after abandoning his KTM MotoGP ride.

Meanwhile, a key factor in the Petronas Moto2 rider selection will be the potential to join its MotoGP team in 2021, should either Fabio Quartararo or Franco Morbidelli depart.