Italian Moto2 rider Celestino Vietti will make an unscheduled MotoGP test debut in the Valencia post-season test, replacing the injured Franco Morbidelli at VR46.
The 24-year-old is one of the riders in Valentino Rossi's VR46 Academy - which includes current MotoGP riders Morbidelli, Pecco Bagnaia, Marco Bezzecchi and Luca Marini - but has not yet been able to find his way onto the MotoGP grid as his career has stalled out somewhat in the intermediate class.
However, Morbidelli's injury right before the start of the season finale - when he crashed into Aleix Espargaro's Honda in its grid slot and broke his left hand as a result - left a vacant bike for the Tuesday post-season test.
And it meant Vietti has been drafted in to join 2026 MotoGP signings Diogo Moreira and Toprak Razgatlioglu as the test's rookies.
Fabio Di Giannantonio will be on the other side of the garage as scheduled. Both Di Giannantonio (contracted directly to Ducati) and Morbidelli (contracted by the team) are locked in at VR46 until the end of 2026.

What is Vietti's track record?
After a decently successful stint in Moto3, Vietti looked on track to join a lot of his fellow Rossi proteges in the premier class when he emerged as a Moto2 title contender in his second season in the category.
But his 2022 flirtation with a title bid proved short-lived, and in the next years, he simply remained an occasional frontrunner in the category, never making a conclusive case to usurp someone like Morbidelli in the VR46 line-up or potentially convince a rival team.
"In all these years, maybe the speed was not the problem - but the consistency was the main problem," he acknowledged earlier this year when asked by The Race what MotoGP still needed to see from him.
This past season from him wasn't the most consistent either, although this was also connected to an overall uneven season by Boscoscuro - one of Moto2's two main manufacturers (with Kalex), whose works team Vietti rode for this year and will continue with in 2026.
He finished seventh in the standings, as second-best of the seven Boscoscuro full-timers - though considerably behind the manufacturer's lead rider Jake Dixon.
Of his MotoGP graduation aspirations, Vietti said earlier this year: "For sure I would be super happy if it [the promotion] happens with VR46. But I understand it's not so easy, because the places are [only] two. The first thing is to try to arrive in MotoGP, but where I don't know. I would be happy anywhere."