Renault has urged Red Bull to clarify its situation regarding Carlos Sainz, or the French outfit could consider an alternative for its 2019 driver line-up.
As a result of last year's late season spell of musical chairs that saw Sainz join Renault from Toro Rosso and replaced by Pierre Gasly, the Spaniard is on loan to the French team but remains contracted to Red Bull.
Should Daniel Ricciardo fail to agree terms with Red Bull Racing, Sainz is first in line to take over the Aussie's drive. That prospect appears unlikely but Renault Sport F1 boss Cyril Abiteboul is reluctant to take any chances, suggesting a bird in the hand is worth two in the bush.
"We're not going to wait forever for Ricciardo and Red Bull to decide," Abiteboul told French daily L'Equipe.
"Either things can be put in place quickly with Carlos, and he would be an extremely serious option for next year, or we will consider alternative options," he added.
If Sainz is called back to the Red Bull mothership, Force India's Esteban Ocon could be considered a serious contender for a seat alongside Nico Hulkenberg, although for that scenario to pan out, the pink panther would likely require a green light form Mercedes to which Ocon remains contracted.
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