Carlos Sainz has signed a contract that could see him join Renault from as soon as the Malaysian Grand Prix it has emerged, with the move part of a deal that will see McLaren use the French manufacturer's engines from next season.

The report by Autosport follows comments by Red Bull Motorsport Advisor Helmut Marko earlier this week which hinted at movement behind the scenes when he claimed the Spaniard's future with Toro Rosso was not 100 percent guaranteed.

The Austrian drinks company had been determined to retain Sainz as back up in case either Daniel Ricciardo or Max Verstappen decided to leave the senior team in the future, however, with Renault wanting an incentive to swap their engine deal from Toro Rosso to McLaren for 2018, the 22-year-old, who was subject to interest from Renault last year, was the carrot that appears to have been taken. 

The report suggested Sainz could make the switch as soon as Sepang in three weeks time, however, that depends on whether Renault is prepared to ditch Jolyon Palmer, a driver that Managing Director Cyril Abiteboul has backed throughout the year.

As for where this leaves Toro Rosso, the Italian team are now set to take over the engine partnership with Honda from next year and potentially secure current Formula 2 driver and Honda junior driver Nobuhara Matsushita.  

That is dependent on whether the Japanese driver can close the 37-point gap to third in the F2 standings, the position he needs to finish to amass enough superlicence points to compete in F1.  

If not, then Red Bull junior Pierre Gasly will likely get the call-up, with the Frenchman racing in Super Formula this season as he waits for his opportunity in F1 after claiming the GP2 crown last year.

The situation could also offer a little insight into the future of Fernando Alonso with Sainz considered the main option to replace the double world champion if he decided to leave. 

Earlier this week, many pointed out changes on Alonso's social media pages which seemed to end all associations with Honda and now as McLaren-Renault in 2018 seems all-but-certain, that activity would indicate he will renew for at least another season.

It also rules out a return for Robert Kubica, at least with the Enstone team, despite a promising test following the Hungarian Grand Prix earlier in the year.