Pierre Gasly has explained the issue that led to a "painful" final laps to the race in Las Vegas.
The Alpine driver was in a promising position at the start when he started from fourth on the grid, and was holding third once the Safety Car period ended.
Alpine elected to keep both drivers out while others pitted during the second Safety Car, with Gasly having to manage 12-lap old Hard tyres.
Teammate Esteban Ocon managed to get them up to temperature quicker, and was subsequently onto the back of him for position. Alpine told Ocon to "hold position" over team radio, but he misheard and overtook Gasly anyway on Lap 33.
"There are quite a few things that were going on, but I think the main thing was after five/six laps I grained the Hard tyre and from there on I just never recovered," Gasly told media, including RacingNews365.
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Gasly: There was a big opportunity on the table
Tyre graining was a concern that was raised among teams prior to the race owing to the low ambient temperatures.
This made things worse for Gasly, who eventually dropped out of the points in P11 as he was chased down by Oscar Piastri who had made a final stop in the closing stages.
"It was just a very painful long last 25 laps," said Gasly.
"Frustrating because the start was great, starting in the right train behind George and Charles not too far away.
"I knew there was a big opportunity on the table, but then after on that Hard tyre it was just pretty much a nightmare."
Carlos Sainz called for a solution to the Safety Car speeds, as he felt that it was going too slow under the tricky conditions.
"I don't know if it was with the Safety Car the tyres get cold, you start pushing on a very cold compound," said Gasly.
"So we need to review, I don't fully understand why I struggled so much on my car."