Mercedes motorsport boss Toto Wolff believes Valtteri Bottas had the pace to be on pole for the second Formula 1 race in succession, had the Finn put his best sectors together.
Bottas qualified third for the Russian Grand Prix, but lapped within a tenth of Ferrari driver Sebastian Vettel's pole position time.
Had he combined the three best sector times he set in qualifying, he would have been ahead by 0.122s.
"I'm very happy with Valtteri’s performance today," said Wolff.
“Sochi is a track that has suited him in the Williams years, probably suits his driving style, it’s a very smooth circuit.
"Balance-wise he felt more at ease with the balance than Lewis, and he wasn’t too far off from pole position.
"If he hadn't done that little mistake of pushing in Q3 he could have been on pole, but could have been doesn’t count.”
Wolff said he was pleased with the way the team had improved the car overnight after struggling during Friday practice.
“I’m very happy how the guys have solved the problem from Friday to Saturday, because we were far behind yesterday, and we’ve chipped it away through the sessions," said Wolff.
“And we also have to find out why the balance on Lewis’s car wasn’t right, not good enough for him.
"As much as I am happy about the steps we have found, it was not good enough to be on pole today, and confidence for tomorrow - it’s very difficult.”
Hamilton said that he had struggled towards the end of the lap when it mattered in Q3, ending up qualifying fourth and 0.573s off Vettel.
This is despite having a car set-up that was similar to that of Bottas.
“I lost about half a second through Turn 13 and 14, but just generally struggled in the last sector," said Hamilton.
"Big snaps, in the last sector, if you see all those little tiny mistakes, it was from the rear end being very weak.”
“I don’t think it was the tyres, it was the balance that we had. [It was a] similar kind of set up of car, but electronically, with the diff and everything, it wasn’t best suited to me."
Hamilton is pessimistic about his chances of challenge the Ferrari's in tomorrow's race.
“Currently we’re fourth, it’s very hard to overtake as it is," he said.
"Their race pace yesterday was better than at least mine. The pace today, I was half a second off, more than half a second off.
“But over tonight we’ll do some studying and try to turn negatives into positives.
"We should hopefully be in a better position tomorrow after the changes we made for today, and hopefully the race pace will be stronger.”