Carlos Sainz could be heading to Renault as soon as the Malaysian Grand Prix, according to reports in the European press on Saturday.
An exclusive story from German language website Motorsport-Total.com says that Sainz' move from Toro Rosso is the linchpin of a complex deal centred on the break-up of the McLaren/Honda partnership.
Sainz had wanted to move to Renault last year. However Toro Rosso has been steadfast in insisting that the Spanish driver is under contract to them for another season. According to the latest reports, the Red Bull management has finally been persuaded to release him early.
If true, it will leave current Renault driver Jolyon Palmer out in the cold. It follows a frustrating season so far for the Briton. But that will just be the first of many shockwaves resulting from the deal, which was reportedly signed on Friday. It has also been approved by McLaren.
Highly rated Red Bull junior driver Pierre Gasly would take over from Sainz at Toro Rosso for the remainder of the season. The 2016 GP2 Series champion has been competing in the Japanese Super Formula Championship, waiting for an opening in Formula 1.
However Gasly's promotion might prove to be short-lived. According to Motorsport-Total.com, Honda protégé Nobuharu Matsushita is to participate in Free Practice 1 sessions with Toro Rosso. The Formula 2 driver could then get his full-time break in Formula 1 next season alongside Daniil Kvyat.
Matsushita had been working with McLaren as part of the Honda partnership arrangement. If he leaves Woking, Formula 3 European Championship leader Lando Norris is likely to take up his development place at McLaren.
The next domino expected to fall is Toro Rosso parting from engine partner Renault. Under the new deal, it will instead receive power units from Honda in 2018. And if all goes well, the senior Red Bull race team could then follow suit in 2019.
Toro Rosso's switch clears a spot for McLaren to receive Renault power units. The team is desperate to end its current arrangement with Honda, which has been beset by chronic performance and reliability issues. Renault had wanted a 'sweetener' such as procuring Sainz to justify agreeing to the deal.
Toro Rosso will need McLaren to supply transmission units to work with the Honda power units. Red Bull management is banking on Honda finally overcoming its various issues within the next 12 months.
Switching to Renault power might enable McLaren to convince Fernando Alonso to stay at the team for another season. His current contract expires at the end of this year, and the two-time world champion has been evaluating his options for several weeks.
McLaren is likely to sign the contract with Renault on Monday. An official announcement is to be expected ahead of the Singapore Grand Prix race weekend.