Bottas had dominated the early stages of the race at Sochi and appeared in control at the front when he suffered a major lock-up into the Turn 13/14 complex near the end of the lap.
Mercedes motorsport boss Toto Wolff said the team's data revealed a worrying tyre situation after that, leading to an intense finish as Vettel's Ferrari closed in.
"He locked both front tyres and flatspotted them, and our metrics showed that it was pretty severe damage to the tyres, which harmed his performance at the end," Wolff said.
"It was a bit of a stressful moment, but he kept it together.
"You could see the pace was still good enough. Sector one was obviously very good, but in sector two he was able to fight back and there was the odd tenth he lost. But on the next lap around he was good."
Bottas explained that the lock-up happened as temperatures began to drop in his front tyres, and the moment briefly took him out of his comfort zone.
Read the full article on eurosport.co.uk: PHOTOS: Bottas had 'pretty severe' tyre damage