Red Bull concerned about power at Monza

'Power' is a keyword in the Red Bull camp on Saturday, after qualifying day for the Italian Grand Prix.

2010 pole specialist Sebastian Vettel, fast all weekend at Monza and never off the first two rows of the grid all season so far, qualified just fifth on Saturday afternoon.

"I don't know where the speed went," said the German.

"I was around 3 or 4 kph quicker yesterday than I was this afternoon with less fuel," he added.

"There are a lot of straights in Monza, so it was quite costly."

Engine supplier Renault has accepted the blame for both of Mark Webber's practice stoppages on Friday and Saturday morning.

Saturday's problem, which doubly worried the team when the Australian's stricken RB6 took a long time to be returned to the pits before qualifying, was caused by a fire inside the airbox.

Team boss Christian Horner admitted the V8 might now have to be run with a "slightly more conservative setting".

Webber qualified fourth on Saturday, crucially ahead of his championship rival Lewis Hamilton.

But asked if he is worried about his engine, he answered: "A little bit, yes.

"We need to look at it with Renault and see what the best plan is. It is not the first time we have seen this, we have experience with this kind of problem and we just need to chip away," added Webber.

Mainly due to Renault's 2.4 litre V8, Red Bull had travelled to the ultra high speed Monza venue expecting its "worst" outing of the entire season, Horner confessed.

"We knew Monza would be a difficult race for us," agreed Fabrice Lom, in charge of Red Bull's supply of customer Renaults.

"Unfortunately we cost Mark some running time yesterday and today, so we apologise for that," he said, albeit praising Webber's efforts to be fourth.

"With Hamilton not at the front, it could be an interesting result," added Lom.