Red Bull cancelled Sergio Perez's media commitments at their home Austrian Grand Prix on Thursday after the Mexican Formula One driver reported sick.
"He became unwell last night and is taking the day to rest to ensure he's in the best possible health for this weekend's race," the team said.
Perez is Max Verstappen's closest title rival but still a massive 69 points behind his double world champion team mate after eight races.
The Mexican needs a strong showing at Spielberg after failing to qualify in the top 10 or stand on the podium in the last three races.
This weekend is the second sprint event of the season and Perez won the first one in Azerbaijan in April, going on to win the Sunday grand prix as well.
That race in Baku remains his most recent win and he has had only one podium finish since then while Verstappen has won the last four.
Friday features a single practice session and qualifying for Sunday's race with Saturday a standalone sprint day.
Sherfane Rutherford struck an unbeaten half-century and Gudakesh Motie produced a brilliant display of spin bowling as West Indies thumped England by 30 runs in a Twenty20 World Cup Group C encounter on Wednesday.
Australia launched their Twenty20 World Cup campaign with a commanding 67-run victory over Ireland in Colombo on Wednesday, powered by four-wicket hauls from Nathan Ellis and Adam Zampa.
Tottenham Hotspur have sacked manager Thomas Frank after eight months in charge, the Premier League club said on Wednesday, after a woeful run of results left the north London club hovering five points above the relegation zone.
South Africa survived Kagiso Rabada's final-over meltdown against Afghanistan and then a double Super Over drama before prevailing in a heart-stopping Group D match of the Twenty20 World Cup on Wednesday.
Pakistan opener Sahibzada Farhan has hit a swift half-century as the 2009 champions comfortably beat the US by 32 runs on Tuesday, clinching their second straight Group A win in the Twenty20 World Cup.