A shock announcement by Yamaha reveals that Maverick Vinales has been 'withdrawn'  from this weekend's Austrian Grand Prix 'due to the unexplained irregular operation of the motorcycle during last weekend‘s Styria MotoGP race'.

The decision casts serious doubt on whether the Spaniard will ever race an M1 again, having already agreed to part ways with the factory at the end of this season, midway through his current contract.

After a strong start in Sunday's first Red Bull Ring race, Vinales stalled ahead of the restart and had to line-up at the end of pit lane.

Vinales then said he struggled with bike problems, a persistent 'pit lane' message on his dashboard and was also given a 'Long Lap' penalty for exceeding track limits, eventually finishing the race in pit lane, in 19th and last.

The Yamaha statement says the decision to effectively suspend Vinales has been made following an 'in-depth analysis of telemetry and data' after the race.

'Yamaha‘s conclusion is that the rider‘s actions could have potentially caused significant damage to the engine of his YZR-M1 bike which could have caused serious risks to the rider himself and possibly posed a danger to all other riders in the MotoGP race.'

The precise nature of Vinales' offending "actions" is unclear, but there are rumours from those trackside that he may have been deliberately revving the bike on the limiter along the main straight rather than shifting to sixth in the closing laps, presumably due to frustration with the technical problems he had encountered.

Whatever the reason, bike problems or something else, during the last three laps Vinales clearly lost significant top speed (his best of the race was 312.1km/h)

Vinales, expected to switch to Aprilia next year, will not be replaced this weekend. His Yamaha future will be decided after a 'more detailed analysis and further discussions'.

Should Vinales not return this season, Yamaha's main option would be to move test rider Cal Crutchlow (currently replacing the injured Franco Morbidelli at Petronas) over to the Factory team. A less likely scenario, which would require permission from Petronas, might even be Valentino Rossi, who is contracted directly to Yamaha and rides a factory M1 of the same spec as Vinales and title leader Fabio Quartararo.

Morbidelli, due to take over from Vinales at Monster Yamaha next season, would have to take his 2019 A-spec bike with him if he switched teams early due to the engine homologation rules, meaning the Italian (due back at Misano) is more likely to remain at Petronas until the end of this season.

The full Yamaha statement regarding Vinales, who won the Qatar season opener and is presently sixth in the world championship, can be seen below:

'Yamaha regrets to announce that Maverick Viñales‘ entry to this weekend‘s Austrian MotoGP event has been withdrawn by the Monster Energy Yamaha MotoGP team.

'The absence follows the suspension of the rider by Yamaha due to the unexplained irregular operation of the motorcycle by the rider during last weekend‘s Styria MotoGP race.

'Yamaha‘s decision follows an in-depth analysis of telemetry and data over the last days.

'Yamaha‘s conclusion is that the rider‘s actions could have potentially caused significant damage to the engine of his YZR-M1 bike which could have caused serious risks to the rider himself and possibly posed a danger to all other riders in the MotoGP race.

'The rider will not be replaced at the Austrian GP.

'Decisions regarding the future races will be taken after a more detailed analysis of the situation and further discussions between Yamaha and the rider.'