Suzuka (Japan): Caterham driver Vitaly Petrov said he was feeling unwell in the run-up to Sunday`s Formula One Japanese Grand Prix.
The Japan race could be crucial for Caterham, who are bidding to retake the tenth place in the constructors` standings that they lost to Marussia in the last race in Singapore.
"I`ve arrived in Japan but I don`t feel well somehow," Petrov said Wednesday on the social networking site Twitter.
"I`ll get some treatment."
Petrov is 21st in the drivers` championship after 14 of 20 races. He currently has no World Championship points this season.