Will Power was conspicuously missing from Sunday morning's half hour warm-up session ahead of the Firestone Grand Prix of St Petersburg, the first round of the 2016 Verizon IndyCar Series championship.
Power broke the track record in Saturday's qualifying session on his way to leading a Penske sweep of the first two rows of the starting grid, but left immediately afterwards after complaining of a 'flu-like stomach virus.
"Unfortunately I've been feeling pretty ill all day," a statement from Power later reported. "It was a struggle to get through qualifying.
"After the Verizon P1 Pole Award presentation I just started feeling a lot worse. I'm sorry I wasn't able to be at the press conference afterward," he added. "I'll try to get some good rest tonight and come back ready to race on Sunday."
However Power was still too ill to take part in the morning warm-up which got underway at 9am local time, and his place in the Penske #12 Chevrolet was taken at short notice by veteran racer Oriol Servia who has made 197 career Indy car starts.
Despite the circumstances, Servia managed to record an impressive ninth fastest time of the session. He was 0.7408s behind AJ Foyt Racing's Takuma Sato who was fastest with a time of 1:01.2361s (105.820mph).
Second fastest for the warm-up was Rahal Letterman Lanigan Racing's Graham Rahal, followed by Ed Carpenter Racing's Josef Newgarden. ANdretti Autosport's Marco Andretti was fourth fastest, 0.0684 ahead of reigning IndyCar Series champion Scott Dixon in the #9 Chip Ganassi Racing Chevy.
Simon Pagenaud - who will be on the front row for the race - was the fastest of the Penske quartet in sixth place ahead of Schmidt Peterson Motorsport's Mikhail Aleshin and KVSH Racing's Sebastien Bourdais.
Behind Servia, the top ten was rounded out by SPM's James Hinchcliffe heading into his first race since suffering traumatic injuries in a practice session for last year's Indianapolis 500 in May.
A decision on whether Power is well enough to get back into the car for a full 110-laps of the 1.8-mile, 14-turn temporary street circuit which is already gruelling enough for the fittest of drivers.
If Servia is not cleared to take part, Servia is expected to take over. The race is due to take the green flag at 12.52pm (4.52pm GMT) and last for two hours.
See full Sunday morning warm-up times from St Petersburg