Red Bull principal Christian Horner has admitted that Daniel Ricciardo's performances in 2014 helped them decide to promote Daniil Kvyat from Toro Rosso.
The Russian replaces four-time world champion Sebastian Vettel, who will race for Ferrari from next season.
However, Horner has revealed that it was the form of the Australian that helped the Milton Keynes-based outfit make their choice.
He is quoted by GPUpdate.net as saying: "The way he [Kvyat] has performed this year has been phenomenal, he's been very quick.
"I think what gave us real confidence was the performance Daniel Ricciardo has delivered this year. Giving him the opportunity has given us the confidence that you can invest in youth and you can believe and trust in it. That's why we've taken Kvyat.
"I've known him obviously since being a member in the Red Bull Junior Team, he drove for my team in GP3 as well, where he won the Championship and his fight back that year from mid-season to the end of the year was truly impressive."
Ricciardo won three Grands Prix in 2014 and was the only non-Mercedes race winner during the season.