Amid intensifying speculation about Pierre Gasly's future, the Frenchman's bosses insist they are still supporting him.

Rumours Gasly could be ousted by Red Bull reached boiling point when Dr Helmut Marko called his performances alongside Max Verstappen this year "unacceptable".

But Christian Horner, team boss, says Red Bull still believes in the 23-year-old.

"We know what he can do as a driver, which is much more than what we have seen so far," he is quoted by Osterreich newspaper.

Horner said Verstappen's win in Austria was particularly tough for Gasly.

"He was in a situation where the harder he tried, the slower he went," he said.

It has even been rumoured that Red Bull could recruit Fernando Alonso, with Marko saying the Spaniard actually approached the team at the end of last year.

But Alonso's past attitude towards Honda soured that prospect, as Marko told motorsport-total.com that the 37-year-old former McLaren-Honda driver is an "absolute no-go" for the Japanese manufacturer.

Marko said: "We are trying to get Gasly up to speed, which is our mission.

"We are changing a lot at the moment, adapting a lot to accommodate him. We want to support him in the best possible way."