Cal Crutchlow will be a test rider for Yamaha next season as he prepares to leave LCR Honda at the end of 2020.
Crutchlow is being replaced at LCR by Alex Marquez after he lost his seat at flagship team Repsol Honda to Pol Espargaro.
Initial reports suggested the British rider, who is 19th in the standings, could compete in MotoGP again next year with Aprilia.
Instead, however, Crutchlow's hopes of an appearance rely on a wildcard or the need for a replacement rider due to his new test role.
Crutchlow started his MotoGP career with Yamaha, spending three years with the team from 2011 to 2013, and a statement on Friday described him as "the ideal rider for the job".
The 35-year-old, who has three career wins, all with LCR, will ride the YZR-M1.
A tough session gets worse for @alexmarquez73!
— MotoGP™ (@MotoGP) November 13, 2020
The @HRC_MotoGP rider suffers his second fall of the afternoon, but is already back in the pit box! #ValenciaGP pic.twitter.com/QtRUyMxMTA
Crutchlow showed he is still capable of competing at the top level as he ran seventh fastest in second practice at the Valencia Grand Prix.
Takaaki Nakagami maintained his recent strong form heading into the weekends as he topped the first session and was only beaten by Jack Miller in the second on Friday.
Miller, who has four retirements this year but has otherwise finished no lower than ninth, was fastest in practice last week.
Joan Mir, who has a maiden world championship title in his sights, came off at the infamous Turn 4 and was only 11th in FP2.
