Red Bull advisor Helmut Marko had earlier suggested Ricciardo had already committed to signing that piece of paper after his participation in the post-Grand Prix test in Budapest the next day on Tuesday.
Pierre Gasly raced in the Japanese single-seater championship a year ago and the Frenchman came agonisingly close to winning the title, missing out by just half a point after the final round was cancelled due to a typhoon.
"I never said I was unloved", he said, in response to one question.
The Austrian admits it is a "pity" to lose Ricciardo who he rates as one of the best drivers on the Formula 1 grid.
He spent two years back at Renault (2008-2009) before going to Ferrari, where he produced some stellar drives only to see Red Bull and Vettel stomp home to four world titles.
"They have a winning mentality and a realistic way of going about it, which I liked". "He was a little bit disappointed I was moving on".
"To be the best driver in the world there are two possibilities: winning eight world championships - quite unlikely now for me - and the second is to taste different series and different cars". It was OK, a call I had to make.
"He spent most of his career at Red Bull and told me he wanted a change, that's right". "It was a very odd situation anyhow", stated Marko while speaking to Austrian broadcaster Servus TV.
McLaren F1 driver Stoffel Vandoorne's manager says that reports that Vandoorne will be replaced by Lando Norris are premature.Amid rumors the British team wants to sign Lando Norris to be Carlos.
"So as I said for me it is a bye bye, but who knows what will happen in the future?"
Marko says Renault's lack of competitiveness means it could be a while before Ricciardo's trademark "shoey" is seen again.
"I think the challenges are probably bigger than the challenges that I can find here for next year".
He said the decision had been a long time coming, rather than one made in the spur of the moment.
"Right now I am thinking that it's a goodbye, but life changes very quickly", he said.
Ricciardo is fifth in the drivers' standings behind the Mercedes and Ferrari pairings. With the contract stuff people assumed I was pretty much done with Red Bull and ready to sign, but I'm pretty sure I always just said I was close to doing something.
"So I just continued to enjoy my holidays, that time I was in Greece".
Alonso said in the Spa paddock on Thursday that Red Bull made multiple approaches for him to become Max Verstappen's team-mate next season, but he turned them down.