Juan Pablo Montoya has dubbed Christian Horner's exit a surprise after Red Bull confirmed the Brit's sacking.

Speaking to Bet Victor Casino, he said: “I think Christian Horner’s sacking has surprised everybody. There has been talk for the last year and a half about them possibly wanting Horner out, because of all the drama happening internally at Red Bull.

“I think there are going to be a lot of changes in Red Bull, they need a lot of changes. The million-dollar question is, have Red Bull got rid of Horner because Max Verstappen is leaving, or did they get rid of Horner to prevent Max from leaving?

"That’s what everyone will be wondering about for the next few weeks or months until we know what happens with Max.

“Anyway, with how hard the Red Bull car is to drive, they need to rebuild their team. You know what I mean, Adrian Newey has left, and they need a new structure to be put in place. In the long term, Red Bull will be okay, but in the short term, they’re going to struggle to put everything in place and hire the right people.

“It’s going to be exciting from the outside to see what happens at Red Bull. I do feel sorry for Christian because of everything he’s done for the team. Everything happens for a reason and we’ll see what happens.

“Overall, I think the sacking has a lot to do with Max leaving Red Bull. Whether it’s about Max staying or leaving, that will be the big question mark everyone is wondering about.”