Michael Schumacher blamed a vibration during his final run for being unable to make it into the top ten in qualifying in Korea.
The German driver will start from 12th position after being unable to complete his final flying lap because of the problem that emerged right after he left the pits.
Schumacher was still positive about having saved a set of super-soft tires.
"To start with the positives of today's qualifying, I have saved two fresh sets of option tires which is always helpful," said Schumacher. "On the other hand, it was obviously a pity what happened. Everything went normally in Q1, and from what you can expect of the tires under normal circumstances, it was absolutely justified to go for just one run in Q2.
"But unfortunately I could feel that something was not right when leaving the pits as I had vibrations straight away. All that was left for us to do was hope that the gap would be big enough to remain in the top ten but that turned out not to be the case. We will now have a close look into what exactly happened and fully concentrate on trying to make up some positions in the race tomorrow."
Mercedes teammate Nico Rosberg had a better session, finishing in seventh position. The German was happy with the result, but admitted it will be hard to do better than that in the race.
"I'm quite pleased with today," he said. "To find the right setup for the qualifying and the race is always a compromise, particularly after such limited dry running, so I'm happy that we saved one set of option tires.
"It will be tough to catch one of the top six drivers tomorrow but hopefully I'll have a good start and may be able to gain a position there. It will be an interesting race from the tire perspective with a lot of stops, and I'm confident that our boys will do a great job in the pits again."