Russian GP: No clear reason for Red Bull's poor qualifying - Vettel

After a difficult Friday, Red Bull looked in slightly better shape in final practice, only to lose ground again in qualifying - where Vettel only managed 11th and his team-mate Daniel Ricciardo was seventh. Both will gain a place via a penalty for Kevin Magnussen.

Vettel said there was more to the problem than the Renault power deficit often cited as Red Bull's shortcoming in 2014.

"We knew that it would be difficult in general for us here with the amount of straights, but equally there are a lot of corners - especially in sector two and three," he said.

"I think we made a big step forward this morning, but I wasn't able to take that forward into qualifying.

"Generally the car felt OK. Obviously it didn't in qualifying, but this morning we were fairly happy and yesterday didn't feel too bad either."

The reigning F1 world champion said his car's performance was getting worse as the qualifying runs went on, contrary to expectations of how the tyres would change.

"It's very different here because you stay out on the same set for quite a while because usually tyres are improving," said Vettel.

"It wasn't the case for me. It was getting more and more difficult as the run went on.

"I think we were just a bit too aggressive. I was struggling with the rear. I couldn't carry the speed into the corners than I was able to this morning."

With one-stop strategies expected for the race and overtaking likely to be tough at Sochi, Vettel doubts he will gain much ground.

"We qualified around P10 because that's as quick as we can go," he said.

"It would be nice to finish on the podium tomorrow but if nothing special happens and we have consistent conditions, it will be very difficult to make a lot of progress."

RICCIARDO: CONSTRUCTORS' BATTLE IS ALMOST OVER

Red Bull's run of four consecutive F1 constructors' championships will end on Sunday unless it can reduce Mercedes' current 190-point lead to 172 or less going into the final three races.

Ricciardo, who still retains a remote chance of the drivers' title as he trails Lewis Hamilton by 73 points with 125 available at present, admitted that Red Bull's form at Sochi so far meant the constructors' fight was basically over.

"If Hamilton wins tomorrow and I stay in seventh, then after that there's probably not much more we can get out of it," he said.

"Even so, it doesn't stop us trying to do our best every race, but it's looking like it's becoming a bit tricky from now."