Ricciardo said: "It was just a bit tricky to drive".
"To come back and get on the podium is really nice".
"Is it going to guarantee closer racing, and cars following closer next year?"
The Red Bull driver was then able to keep Vettel behind in the closing stages, despite the German having the advantage of fresher rubber.
Horner feels the changes are a knee-jerk reaction to the lack of passes at the season-opening Australian Grand Prix, and says the sport has made an "irresponsible" decision with concepts likely to cost teams "millions of pounds". It's just all a bit more painful for us.
"After that I could settle down and concentrate on my own race". Speaking after qualifying, he said: "I still don't know what the faster tyre is to be honest". It completely changes the philosophy of the auto because the front wing will be wider and different. Remember that stern talking to - complete with finger-wagging - you received; the one that went "don't touch this" and "don't do that" because she'd know, and "woe betide you" if you disobeyed?
"It is a little bit disheartening as I don't really know what I could have done more with what we have".
"It's never enough but it's a good step", he said.
Buffon hit with UEFA charges after Madrid fury
He was sent off before Cristiano Ronaldo scored from the penalty spot to send Madrid through 4-3 on aggregate to the semifinals. UEFA says the case against Buffon relates to " general principles of conduct " and his red card for confronting the referee.
"We both put good laps on the Supersofts in Q3".
He stated: "Monaco should be our strongest circuit to date on raw pace but we'll see".
"How far are we off [Mercedes and Ferrari]?"
Nevertheless, after the two drivers qualified within 0.002s of each other in fifth and sixth on the Barcelona grid, Ricciardo is expecting rules of engagement to be laid down in Sunday's pre-race briefing.
But while Max Verstappen might have claimed his first podium finish of the season in third, a disappointing performance in qualifying and a deficit of nearly half a minute to race victor Lewis Hamilton mean the Milton Keynes outfit are still some way off where they want to be.
The two Red Bulls started the race in P5 and P6, and stayed there until Kimi Raikkonen's mid-race retirement, but they had the pace for the early stages.
Much of the Red Bull boss' attention was on the future, however, as he considered where the team has to go from here to be more competitive.