Alexander Albon says "it hurts" after he was replaced at Red Bull by Sergio Perez for the 2021 season.
British-Thai Albon, 24, was demoted to be the team's reserve driver as 30-year-old Mexican Perez was brought in to partner Max Verstappen.
"I gave it everything out there, but it wasn't quite enough," said Albon on social media.
"I have more to give and my focus is getting back for 2022 and to wave the Thai flag again."
Albon was out-qualified by Verstappen at every race in 2020, and was on average 0.523 seconds a lap slower.
In races, while Verstappen took two wins and nine other podiums finishes in 17 races, Albon's best results were two third places in the Tuscan and Bahrain Grands Prix.
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