The Portuguese rider, born in Almada, is suffering from an injury to his left shoulder following a crash caused by a collision with Spaniard Fermin Aldeguer (Ducati) in the sprint race of the Argentinian GP.

Over the next few days, the rider will undergo further tests to monitor his progress, the statement said.

The team's sports director, Italian Gino Borsoi, said he was ‘very sorry to hear about the injury suffered by Miguel Oliveira, not least because it happened at a time of the season when he was gaining more and more confidence with Yamaha’.

Augusto Fernandez, 27, hails from Madrid and is a test rider for the Japanese brand, having left KTM at the end of last season.