Niki Lauda said he had a lot of sympathy for Nico Rosberg at the Russian Grand Prix after throttle issue saw the German retire from the lead of the race.
Rosberg took his second consecutive pole position at Sochi and was leading the opening laps of the race before his throttle started to jam open. It became increasingly difficult for Rosberg to control the car and by lap seven he had lost position and returned to the pits to retire, effectively killing off his title chances this year.
"I feel really upset and sad for him because when you are in the lead and you can win a race and you lose it like this, it's bad," the Mercedes team chairman said. "But we have to find out what the cause was - I know it was a throttle pedal problem - we've got to fix it and make sure it doesn't happen again."
As for Lewis Hamilton, who now looks locked on for a third world title, Lauda said he could not fault his lead driver's approach this year.
"He's doing a perfect job, nothing more to say. Here he won the race, in the lead of the championship and no complaints whatsoever."
Unlike 2014 the two Mercedes drivers have not made contact on track or had many flashpoints away from it.
"Yeah, this is what we all try to do - everybody here - to be better than last year and it is going very well," Lauda added. "I can't complain."