As quadruple world champion Sebastian Vettel departed for Ferrari, Red Bull officials said they took merely "ten minutes" to decide that Russian rookie Daniil Kvyat would be promoted from the junior team Toro Rosso.

That is partly because the energy drink-owned premier team said Daniel Ricciardo, having dominated Vettel in 2014, is now fully ready to step into the leading role.

"In the beginning, although we knew he would be quick, we did have doubts as to whether he (Ricciardo) would be as fast in the races as he is in qualifying," team boss Horner told the French magazine Auto Hebdo this week.

He's good, he's fast, and he doesn't care what people think of him. Christian Horner

"But he has achieved outstanding results this season. Just looking at Daniel, you know he is going to be successful - his smile says a lot."

So Horner said 20-year-old Kvyat, although just a single year out of GP3, is now ready to step into Ricciardo's role at the senior team.

"Daniil is a very exciting young talent," he said. "He's good, he's fast, and he doesn't care what people think of him.

"He has a similar mindset to Kimi Raikkonen," Horner revealed.