Ricciardo future must be decided by August - Red Bull

Red Bull cannot afford to let uncertainty over Daniel Ricciardo's future go on beyond August, team principal Christian Horner has warned. The Australian's contract expires at the end of 2018, with Ferrari and Mercedes reportedly waiting in the wings to swoop for the six-time grand prix winner.

Ricciardo has routinely stated that he is looking to put himself in the seat with the most chance of regular success in 2019, continuing the kind of success he enjoyed at the Chinese Grand Prix could convince him to remain with his current employers.

However, with Valtteri Bottas and Kimi Raikkonen's Mercedes and Ferrari futures respectively uncertain into next year, a seat at Red Bull's rivals could also be on offer.

Ricciardo has followed the lead of world champion Lewis Hamilton by stating he is uncertain over committing to Formula 1 beyond 2020, with Liberty Media planning to shake the sport up with a raft of regulation changes.

In pre-season Red Bull advisor Dr Helmut Marko said a deadline had been put in place for talks with Ricciardo to be finalised and Horner may have let us in on the cut-off point.

"There should be a decision by the summer break at the latest. We do not want to wait forever. We have other good options," he told Auto Motor und Sport.

"Our priority is to continue working with Daniel, but if that doesn't work out, we'll look to those other options."

Horner continued on a recurring theme when outlining the options available to Red Bull next year.

He said: "The most obvious is Carlos Sainz. He is under contract to us. And then we have a few young drivers."