No one was looking particularly happy or thrilled in the Red Bull garage after qualifying for the Spanish Grand Prix at the Circuit of Catalunya in Barcelona.

Tyre concerns left Sebastian Vettel unable to make a serious qualifying run in Q3 and his team mate Mark Webber failed to win have the opportunity to try after being caught out and eliminated in Q2.

"From Q1 onwards we decided to go on the soft tyres," explained the German world champion of the furious strategic thinking that had gone on during the qualifying hour. "The first run in Q2 wasn't good enough, so I had to go again and it was clear then that if we made it to Q3, we wouldn't have any new soft tyres left."

Sure enough, Vettel was left making what amounted to little more than a sighting lap to chalk up some sector times in Q3 to put them ahead of anyone who didn't come out of the pits at all - such as Kamui Kobayashi, whose Sauber was still stuck out on the side of the track after a hydraulics failure in Q2. Michael Schumacher adopted a similar strategy to Vettel.

"We knew we had to run again with Seb and he did just enough to make it into Q3, but he'd used all his sets of soft tyres, at which point it became a game of tactics," explained Red Bull team principal Christian Horner. "Mercedes were in the same position as us with tyres and were the only one we could potentially out qualify. We performed an out and in-lap to make sure we were the first to do that and then started a timed, but Seb was down compared to Rosberg - the the only other scrubbed tyre user - so we aborted the lap

"I think we got the maximum at the end there in Q3, we saved some sets of tyres, which we thought going in to qualifying would be crucial," added Vettel. "Tyres will be important tomorrow, so let's see what we can do."

In any case, he didn't think that they could have done much better today even if they'd had more tyres available to them: "We didn't have the pace of the top five cars today, he confessed. "A pretty different session today; it was extremely tight."

Just how tight was illustrated by the misfortune of his team mate Mark Webber, who was caught out by a late flurry of fast laps at the end of Q2 which saw him bumped out of the top ten with two little time to take to the track himself.

"I'm pretty surprised by that," the Australian admitted. "We were quick, but the track kept getting faster and we got caught out. My first timed lap in Q2 wasn't fast enough. I was P2 after the first lap and we thought we had done enough, but in the end it wasn't.

"I was told not to go out again, but the way that the track improved was a surprise to all of us," he added. "It's the way it goes sometimes."

"A difficult session," admitted Horner. "In Q2 we thought we had done enough with Mark, we knew it was going to be tight, but we thought the time was enough and were keen to take a new set of tyres into Q3, but it didn't work out and we missed the cut with him."

Horner's view was echoed by Cyril Dumont, Track Support Leader and engineer for Red Bull's engine suppliers Renault, who said that it has been a "disappointing day."

But Horner himself was already looking on the bright side of a difficult day at the office for the championship-winning team: "We have four new sets of tyres for Mark and three for Sebastian, which can be extremely valuable in the race," he added.