Early on Monday, having learned the bad news only at midnight after Sunday's race, the 24-year-old told the local Herald Sun: "I'm not really in a place ... not in the mindset to talk about it right now."
But after jetting from Melbourne to his native Perth for a few days of training before Malaysia, Ricciardo told the West Australian newspaper that he is confident Red Bull will prevail.
"Otherwise they wouldn't (appeal). It's a lot of time for them and some money as well so they have confidence that we can turn it around, but it's going to take a while until we know," he said.
F1's other two engine suppliers, however, are siding with the FIA, despite Red Bull team boss Christian Horner insisting all three manufacturers had trouble with the mandatory fuel flow sensor in Australia.
But Ferrari's Stefano Domenicali said: "We need to rely on the fact that it is a situation that is well managed by the FIA."
And Mercedes' Toto Wolff was also quoted by the Guardian newspaper: "The FIA is obviously controlling fuel flow and checking with all the teams, and it is a question of learning by doing it between the FIA and the teams."
But Ricciardo said he thinks Red Bull has solid grounds to be unhappy with the Melbourne ruling.
"They feel that it's not black or white, it's a little bit shaded, so that's why they're going to fight it and we'll see how they go," he said.
It could take some time before the FIA schedules the actual appeal hearing, but Red Bull's Dr Helmut Marko thinks the matter needs to be at least clarified urgently.
"The device that measures the flow rate has weaknesses," he told Kleine Zeitung newspaper. "In our opinion we were within the regulations.
"This has to be clarified by the next race, because at the moment there is not a reliable measurement," Marko insisted.
F1 chief executive Bernie Ecclestone, meanwhile, thinks the entire rule limiting the flow of fuel into the engine should be scrapped.
"The whole regulation, to me, seems a bit of a joke," he told the Mirror.
Ecclestone said he thinks the rule limiting each car to just 100 kilograms of fuel per race is enough.
"If you use too much you are going to run out of fuel. It seems to be that simple and if it isn't, it should be," he said.