Carlos Sainz believes he was on course to make it into the final round of qualifying in Bahrain - until his car ground to a halt at the end of Q1.
Sainz was halfway through an impressive flying lap when the Toro Rosso lost power. He said that he has "absolutely no idea" what had caused the failure. It leaves him starting tomorrow's Grand Prix from 16th place.
“We really need to investigate all these problems because we lost a great chance today of a Q3,” he told the BBC. "The car is the fastest we’ve had since Australia, so it's a big shame.
"To be only able to do a couple of laps in quite unfortunate," he added. "How frustrating and annoying!
Sainz insisted that if the car hasn't broken down he would have made it into Q3 and started from among the front four rows.
"I'd say the top eight was possible," he said. "I'm disappointed, as I was doing a great qualie ... It's a real shame that I had to stop the car.
"We had got up to speed very quickly after yesterday's problems and I was coming very fast, but another reliability issue puts us only P16 on the grid.
"The only positive is that the race is tomorrow and we can still fight for something," he continued. “I don’t know how much because obviously because this year it’s difficult to overtake, tougher to do good recoveries.
"Once I cool down I will get over this, stop being upset about the situation and already start thinking about the race
"I think the car has a lot of potential here. It feels faster than ever since Australia," he suggested. "I’m going to do my best and see what I can do.
"I will push hard, even if I will go a bit into the unknown after missing so much track time. There will be a lot of improvisation, but we've done that before and we've come along pretty well
"Tomorrow is time to try and recover," Sainz concluded. "I'm positive that tomorrow can end up being a good day."
GALLERY: All the pictures from Saturday in Bahrain
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