Charles Leclerc has revealed his Austrian Grand Prix gearbox change penalty was triggered by a suspension failure on his Sauber Formula 1 car.
Leclerc had looked set for another strong showing in qualifying at the Red Bull Ring, but his Sauber stopped on track on an out-lap at the end of final practice.
Sauber discovered that the gearbox failure had been caused by a problem with the rear wishbones, with Leclerc saying the team "haven't understood yet what happened" but knew its root cause was the suspension.
Asked by Autosport about whether the breakage could have been caused by kerb damage, Leclerc said: "This time we don't really know. We need to investigate. We haven't understood yet what happened.
"Something broke in the suspension, in the triangles [wishbones], a triangle broke and that ended up in a gearbox failure."
Leclerc managed to qualify in 13th place, but will start down in 18th with the five-place penalty for changing the car's gearbox before it had completed the mandatory six consecutive events.
Being so far back on a weekend where his car has looked competitive has left Leclerc feeling he may need to take some chances to continue his points run.
"I will have to take some risks at the start," he said.
"Hopefully we will have a good start, a good first lap. It is quite optimistic to target points tomorrow. It is still the target, but will be very difficult to get them."
Leclerc still starts ahead of team-mate Marcus Ericsson, who was at a loss to explain why his good form in practice was not carried over into qualifying as he ended up slowest overall.
"We are trying to understand now why we were struggling so much in qualifying," he said.
"All weekend we have been looking really good, and looked strong - right there in the mix in midfield and looking strong.
"But then in qualifying we struggle compared to the others to take the step that the others seem able to do. So at the moment we don't really know why or what is the reason for it.
"I was happy with the balance and the driving felt good. The stopwatch was not the good thing, but the rest felt quite alright. That was the problem."