Lewis Hamilton has pulled out of a tyre test in Barcelona to rest a sore foot before next week's US Grand Prix.
The Mercedes driver was due to test the 2017 Pirelli tyres with a modified 2015 'mule' car on Wednesday, but team-mate Nico Rosberg took on those duties.
Hamilton, replaced by reserve driver Pascal Wehrlein for Thursday's test, is 33 points behind Rosberg in the world championship with four races remaining.
Mercedes said there was "no concern" over Hamilton, 31, for the Austin race.
"Lewis had some discomfort in his foot after training on Tuesday," said a team spokesman.
"It was agreed he wouldn't test so he could rest it and get physio to be in good shape for Austin, which he will be."
Hamilton was criticised at the last race weekend in Japan for playing on social media platform Snapchat during a news conference.
The three-time world champion then walked out of a media briefing on Saturday, before hurriedly leaving the circuit after the race to fly back to Europe.
The US Grand Prix in Austin takes place on Sunday, 23 October.
Subscribe to the BBC Sport newsletter to get our pick of news, features and video sent to your inbox.