But we reported last week that the 21-year-old has actually struggled recently in the Formula Renault 3.5 series.
And the next Red Bull youngster in the queue, Carlos Sainz jr - the 18-year-old son of the Spanish rally legend - has already been ruled out by Toro Rosso boss Franz Tost.
"I assume that he could be at formula one maturity in about two or three years," Tost said in July.
Another candidate is the Brazilian GP2 star Felipe Nasr, who according to Germany's Auto Motor und Sport is knocking on the door with backing from Banco do Brasil and Sky Brasil.
"I need a Brazilian driver," said F1 chief executive Bernie Ecclestone in August.
Tost said on Wednesday the Faenza based team is not ready to name Ricciardo's successor.
"We will look at all our options and make a decision at a later date, as there is no immediate need to rush," he said.
But Austrian Tost seemed to play down Nasr's chances by insisting that, when Dietrich Mateschitz bought Minardi in 2005, he wanted it to be "the final step" in the Red Bull driver development programme.
"Daniel's move thus vindicates the work of the programme and also proves that we at Toro Rosso have given him a good racing education," he said.
But although well prepared, Ricciardo may take some time to adjust to his new role alongside Sebastian Vettel at the world champion team.
Dr Helmut Marko said the 24-year-old will be given "three to five races" to get up to speed.
Australia's 1980 world champion Alan Jones thinks he might need longer.
"There's been a lot of kids go into that (Red Bull young driver) programme and have never survived it -- and Daniel is one that has," he is quoted by the Melbourne newspaper The Age.
"If it takes Daniel twelve months or thereabouts to get into the groove with (Red Bull), I think they've probably factored that in."
Another Australian, McLaren sporting director Sam Michael, also thinks Ricciardo will need some time.
"If he came in and performed right at Sebastian's levels straight away then I think it would be quite amazing," he told reporters during the Vodafone teleconference on Wednesday.
"But ultimately, it's grand prix racing so it's also survival of the fittest. He'll be in there to prove himself as quickly as possible," said Michael.