Christian Horner: Renault's management frustrated Max Verstappen

Verstappen was not shy in giving his often critical thoughts of Renault, who supplied Red Bull's engine before Honda took over at the start of the 2019 season.

"Max was enormously frustrated by Renault and the management of Renault," Horner said to F1 Racing. "Max just didn't feel like they were listening to his concerns about the driveability. In addition, reliability was naturally frustrating for him too. In the end, he lost confidence in what he was being told."

With Daniel Ricciardo switching from Red Bull to Renault at the same time they switched power unit suppliers, this allowed Verstappen to come out of Ricciardo's shadow a bit more, Horner has also stated.

"Daniel is such a big character, Max was a bit like his younger brother," the Red Bull team principal said. "When Daniel left the team, Max was really in a responsible position. I had the feeling that he had just become one step more mature and he has now proven to be able to show that responsibility and that strong leadership from the cockpit."