Red Bull Formula 1 boss Christian Horner says Alex Albon's retirement from the Eifel Grand Prix was triggered by debris puncturing a radiator.
Horner believes that the Red Bull driver would have been challenging for a podium had he not retired - despite an early pit stop that compromised his race.
Albon locked up on the first lap and the subsequent vibration issue led to a pitstop on lap eight, which was significantly earlier than planned.
He dropped to the back of the field but was making good progress and had survived contact with Daniil Kvyat, which earned him a five-second penalty, when he was called into the pits due to rising temperatures.
"He had a big lock-up into Turn 3 on the opening lap and our concern was that he had gone pretty much through to the canvas," said Horner. "We were seeing vibrations increasing to the point that it was past our threshold.
"So from a safety point of view, we had to pit him at that point. He then started to make good progress back through the field, but was very unlucky in that he picked up some debris that has pierced the radiator on the cooling circuit, and we just saw our temperatures starting to go sky high. Before losing an engine it seemed we had no choice but to stop the car.
"It was a shame in the race, I think he would have been racing [Sergio] Perez and [Daniel] Ricciardo even with that flat spot and early stop. It was a shame for him not to see that come to fruition today, because he's had a pretty sensible weekend.
"He was almost on the second row of the grid yesterday, a few hundredths of a second off that, he was a lot closer to his team-mate than he was in Russia. So I think it's a shame that he didn't get a result out of today, because I think there was more to come."
Albon had undergone a chassis change on Friday, with the team having planned to run alternate suspension set-ups on its two cars but running was limited due to both of Friday's practice sessions being cancelled.
"We wouldn't have boxed if there was no issue," said Albon of his problem in the race.
"Obviously, we had the lock up in lap one so [that] just compromised the race really. It was a bit of a shame, obviously the car is quick.
"Without having this issue we could have done something. We were pretty slow with the flat spot, so I'm sure there was pace in the car there."
Regarding the clash with Kvyat, he added: "We had a good restart, and obviously Dany run a bit wider in the chicane. And a bit of misjudgment on my side."