Miller's three-year factory Honda deal expires at the end of this year, but is not set to be renewed after the Japanese manufacturer chose to lend its backing to LCR rider Cal Crutchlow for 2018.

That meant Miller had to reach a deal with Marc VDS directly, but instead he took up an option to join Pramac, which is known to have been courting the Australian rider for some months.

Motorsport.com understands Miller had to inform the Italian squad by Sunday afternoon of his choice, or else Pramac would have moved to secure Tito Rabat's services for next season.

At no point during the discussions did Pramac consider renewing Redding's contract, whose best option now appears to be to return to the Marc VDS squad, where he raced in 2015.

This change makes sense considering that the Belgian squad's team principal, Michael Bartholemy, is also the agent of the Gloucestershire rider.

In any event, Miller would arrive at Pramac as the number two rider on a year-old bike, while teammate Danilo Petrucci gets the factory-spec 2018 Desmosedici after signing to stay at the team last weekend.

Rabat set for Avintia move

Miller's current Marc VDS teammate Rabat is now poised to join Avintia Ducati, where he is expected to ride one of the squad's 2017-spec Ducatis. Incumbents Hector Barbera and Loris Baz are among the candidates to be on the second bike.

At Aspar, Alvaro Bautista has finalised a deal to remain on board, despite being courted by Aprilia, but it is not clear yet who will ride the second bike, even if Karel Abraham has the backing to stay.

Nor is it known who will be Aleix Espargaro's teammate at Aprilia. Both Bautista and Petrucci turned down the chance to join the Noale squad, but Sam Lowes remains vulnerable despite having a two-year deal in place.

One of the final remaining questions about the 2018 grid is if LCR expands to a second Honda. If so, Japanese Moto2 rider Takaaki Nakagami would likely become Cal Crutchlow's teammate at the Monegasque team.

Translation by Irene Aneas

2018 MotoGP rider line-up so far:

Team Riders Repsol Honda Marc Marquez Dani Pedrosa Movistar Yamaha Valentino Rossi Maverick Vinales Ducati Andrea Dovizioso Jorge Lorenzo Suzuki Andrea Iannone Alex Rins Aprilia Aleix Espargaro Sam Lowes* KTM Pol Espargaro Bradley Smith LCR Honda Cal Crutchlow Takaaki Nakagami Marc VDS Honda Franco Morbidelli Scott Redding? Tech 3 Yamaha Johann Zarco Jonas Folger Pramac Ducati Danilo Petrucci Jack Miller Aspar Ducati Alvaro Bautista TBA Avintia Ducati Tito Rabat TBA

* Under contract but ride thought to be uncertain