Just as Christian Horner and Lewis Hamilton were diffusing the rumours, Red Bull's Dr Helmut Marko was stirring them up.
"It is our goal to have the two best available drivers, and it's also good for Vettel to work with the very best," said the outspoken Austrian.
"I think everyone in the paddock at the moment is interested in getting a seat at Red Bull," he added.
The comments were doing the rounds in the Valencia paddock along with the cover of the Austrian magazine Sport Woche, depicting McLaren's Hamilton mocked up in a pair of Red Bull overalls.
The 2008 world champion had met with team boss Horner in the Red Bull motor home for between 5 and 15 minutes in Canada two weeks ago.
Horner admitted the visit was a "surprise" but would not talk about what was discussed. Vettel is under long-term contract and the Briton said Red Bull is "very happy" with Mark Webber.
"Of course, there are always positives and strengths you can have to help you in negotiations with your team, but that wasn't the aim," Hamilton said in Valencia on Thursday when asked if he is using the Red Bull rumour to get more money from McLaren.
"Definitely, hopefully, by the end of the year I'll have something in place and I can continue on," said the Briton.
The other big rumour on Thursday was that Hamilton's teammate Jenson Button is either on the verge of getting a lucrative new McLaren contract, or kicking off talks with Ferrari.
The 2009 world champion said the latter speculation is "hilarious because it's not true.
"I don't know who put that out there, but it wasn't us and it wasn't Ferrari. I think it's just some column inches," said Button.
He indicated the next step will be sitting down with his current boss Martin Whitmarsh.
"I'm sure we're going to have to talk about it soon because it's been mentioned so much in the press. We didn't plan on talking about it quite yet," said the 31-year-old, who can be retained by McLaren in 2012 due to a contract option.