Carlos Sainz Jr is in the frame for a seat at McLaren in 2018 if Fernando Alonso leaves the team at the end of the 2017 Season according to Josep Viaplana - the F1 correspondent of Spain’s Diario Sport.
"Sainz is among the drivers who have made the most progress in recent seasons, despite his modest Renault-powered Toro Rosso," Viaplana said. "Red Bull knows he (Sainz) cannot stay a fourth year in Toro Rosso. Helmut Marko and Christian Horner have already decided that if Ricciardo and Verstappen stay at Red Bull Racing, they will open the door for Sainz to look at a better option."
Sainz entered Formula 1 in 2015 as part of an all-new driver lineup at Toro Rosso to partner Max Verstappen and has remained there since. Despite having midfield machinery, Sainz has consistently impressed onlookers, leading to the Spaniard being linked to a place at Renault and Ferrari in recent years due to the poor performance of Jolyon Palmer and the looming retirement of Kimi Raikkonen. As Daniel Ricciardo and Max Verstappen are committed to Red Bull Racing for the foreseeable future, a promotion for Sainz to the senior team looks unlikely.
The reports that Sainz is in the frame for a seat at McLaren in 2018 are a result of the situation that the team is currently faced with, having struggled at the back of the grid since 2015 due to their unfruitful relationship with Honda. This has in turn led to rumours that Fernando Alonso will be leaving the team at the end of 2017 due to the poor performance of McLaren and his three-year contract coming to an end at the end of this season.
Due to a three-year stint with Honda which has seen very little success, it has also been rumoured that the team will split with the engine supplier, with it being possible that Mercedes could renew their relationship with McLaren in 2018 to supply them with customer engines.
This relationship renewal is something that Mercedes team boss Toto Wolff is reluctant to talk about however, being quoted by the Spanish Marca sports newspaper that: "If you are considering a new girlfriend, you first want the couple to divorce before jumping into bed. It's not our priority at the moment. The most important thing is for Honda to improve, to continue in the sport and to have a good deal with its customers or teams. We do not want to interfere at this stage."