Max Verstappen's bid for victory in Formula 1's 2019 United States Grand Prix was hurt by floor damage he picked up early in the race.
Verstappen was Mercedes' main challenger at Austin, but just missed out on being able to take second place back from Lewis Hamilton on the final lap as yellow flags at the end of the track's main straight for Kevin Magnussen's stranded Haas prevented him from making a pass.
After the race, it was discovered that the balance of Verstappen's car had been affected by a broken floor, although the team is not sure what caused the damage.
Red Bull team boss Christian Horner said: "We had a pretty decent weekend, qualifying within a few hundredths of the pole, but we have lost a big chunk of the rear floor quite early-on in the race.
"We damaged the front wing endplate with a touch [with Bottas] at the first turn, and then we have had some rear floor damage, which I don't know if that was the result of that or running wide at the first turn.
"But from about lap five onwards we saw a drop in load and there is a big hole in the floor that is missing."
Verstappen said the floor damage caused his car to behave in a "weird" way that he had not experienced before.
"I was just struggling with some weird oversteer in the car," he explained.
"Initially, they said it was my front wing, which had a little bit of damage but after the race I looked at the car and I was missing a big piece of my floor in front of the rear tyre, so that definitely cost me a lot of lap time today.
"I don't know when it happened, but already quite quickly into the race I had this weird behaviour from the car, which I had not felt before.
"So that's a bit unfortunate and otherwise I think we could have been stronger." Horner said that the biggest consequence of the floor damage was not lost lap time, but that the balance change had consequences in terms of tyre management.
"It is difficult to quantify the performance, but definitely, it made us slightly heavier on deg because the balance shift was quite significant," he said.
"Max was obviously closing down Lewis at the end of the race there, as Lewis looked like he was running out of tyres.
"But then unfortunately the combination of backmarkers and yellow flags, it muted the race right in the last couple of laps."