Jonas Folger will sit out the 2018 MotoGP season in order to fully recover from an illness which forced him to miss the final four races of his maiden campaign last year.

The German stepped up to the premier class alongside reigning double Moto2 world champion Johann Zarco to the Tech3 team in 2017, and proved to be an impressive addition to the grid, narrowly missing a maiden win at the German Grand Prix to Marc Marquez.

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Signed up for another year soon after his home podium, Folger’s future looked bright. However, he was struck down by Gilbert Syndrome, something that went undiagnosed for several years, ahead of the flyaway races and was forced to miss those to undergo treatment.

Folger was expected to return to action for the first pre-season test of the year at Sepang in January, but has since decided to focus his attentions on finding permanent solution to solving his medical issue having failed to make the recovery he was hoping.

“I’m incredibly sad to be saying this, but I will not be racing in MotoGP in 2018,” the multiple 125cc and Moto2 grand prix winner said.

“I wasn’t able to make the improvements I was hoping for, and at this stage I don’t feel able to ride a MotoGP machine at 100 percent.

“I’d like to thank everyone involved, but especially the Monster Yamaha Tech3 team, Yamaha Factory Japan, Monster Energy, HJC, IXON, Forma Boost and Rudy Project.

“I hope to be back one day and want to thank you all for your ongoing support.”

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Tech3 team boss Herve Poncheral expressed his shock at the news, but respects Folger’s decision.

“Last night (Tuesday) I received a call from Bob Moore, Jonas Folger’s personal manager,” he said.

“I couldn’t believe what Bob was telling me on the phone, that Jonas Folger has decided not to race the 2018 MotoGP season because he doesn’t feel 100 percent mentally and physically recovered.

“It is still very difficult for me to believe, that he’s not going to race with us in 2018, especially because he has been somebody I had a lot of faith in and I was sure we would reach the top level together this year. I completely respect his decision, although it’s hard to swallow.”

Poncheral added that no decision on a replacement for the German has been made yet, and admits finding a suitable replacement will be difficult due to contracts already being in place for this year.