Max Verstappen is rumored to be against seeing his former Toro Rosso team mate Carlos Sainz fill Red Bull Racing's second seat in 2019.
Daniel Ricciardo's unexpected departure from the Milton Keynes-based squad has worked the drivers' market into a frenzy, with numerous opportunities for change suddenly emerging.
Earlier this summer, Red Bull's Christian Horner stated that Sainz - who remains contracted to the energy drink company - would be the team's most likely choice in the event of Ricciardo's departure.
However, according to Spanish daily Marca, the Verstappen camp is very much against the idea of reuniting the Dutchman and Sainz, the pair enduring a difficult relationship in their final months together at Toro Rosso in late 2015 and early 2016.
Verstappen's negative view of Sainz could play into the hands of Pierre Gasly, while the 23-year-old Spaniard could find refuge over at McLaren, where Zak Brown has already partly opened the door.
"We think Carlos is an excellent race car driver," said Brown last weekend in Hungary.
"He's certainly someone that as you go down the shortlist of drivers you’d consider putting in a race car.
"If he was free, and if we had a seat, he would certainly be high up on the consideration set."
Should Sainz eventually head to Woking, the identity of his team mate is also the subject of much speculation given the uncertainty surrounding the future in F1 of Fernando Alonso.
"We do have a long-term agreement in place with Stoffel and Fernando, but as you can imagine in these contracts there’s a variety of elements to them," added Brown.
"We will make our driver decision ultimately when we’re ready. I anticipate that being some time after the summer break.
"We’re still reviewing, analysing what’s ultimately the best combination for McLaren moving forward. Stoffel is very much part of that consideration set."
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