World champion Marc Marquez will not start the Andalucia MotoGP in Jerez after dropping out of qualifying on Saturday four days after an operation on a broken arm.
"I understood that it would be very difficult to ride the bike and to finish the 25 laps in the race," Marquez said.
"But after surgery I saw there was a small possibility," he said. "When you are a sportsman, and you have a passion, you try."
The six-time world MotoGP champion broke his right arm in a crash at the delayed season-opening Spanish Grand Prix on the same track last Sunday and underwent surgery on Tuesday.
He was declared fit to race on Thursday after passing a medical which, he said on Saturday, included 40 push-ups using his broken arm.
"A champion cannot stay at home if he thinks he has the option or a slight chance," Honda boss Alberto Puig said after Saturday's qualifying.
The Honda rider sat out practice on Friday and struggled in Saturday's third session before dropping out of opening qualifying without recording a time.
Frenchman Fabio Quartararo, who won his maiden MotoGP race last week and rides for the Yamaha satellite team, grabbed pole with a lap of 1min 37.007sec to edge Yamaha's Maverick Vinales by 0.095sec.
Francesco Bagnaia, an Italian with Pramac Racing, was third fastest, 0.169sec behind Quartararo, to complete the front row of the grid. Veteran Italian Valentino Rossi was fourth for Yamaha.
In the opening practice session of the morning, Marquez managed only the 20th best time, 1.3sec behind Vinales, who set a course record.
"I was kind of surprised at being able to ride in a good way," Marquez said.
In the second session, Marquez began to struggle, slowing on corners and swinging wide.
"When I went out again immediately there was a big pain in the elbow, not the bone. My body at that moment said stop," he said.
He started the first qualifying session but returned to the pits without posting a time.
"I followed my instinct," Marquez said. "My instinct said go to Jerez. It's what I did. My instinct today said ride the bike. It's what I did. My instinct in Q1 said stop and I did."
"I will sleep well because I tried and now I know I couldn't."
- 'I will fight hard' -
If Quartararo wins on Sunday, he would hold a 50-point lead over Marquez going into the Czech Grand Prix at Brno on August 9.
"Of course Marc is a rival for the title," the Frenchman said.
"Certainly two blank results are difficult in this kind of championship because it will be rather short but we know Marc's potential."
Marquez said he was starting preparing.
"I will not be 100 per cent but I will fight hard," said.
A bad qualifying session for the Marquez family ended with younger brother Alex heading for a medical examination after crashing his bike on turn five. Honda quickly tweeted that "Rider OK."
Alex Marquez did record a time, but it was the slowest of the qualifiers and left him 21st and last on the grid.
Two other riders nursing injuries made the starting grid.
Briton Cal Crutchlow of the Honda satellite team, who underwent wrist surgery in the week, qualified 13th and Spaniard Alex Rins, on a Suzuki, was 20th despite his fractured and dislocated right shoulder.
"The injury is taking it out of me and it's very painful, but I knew it would be hard," said Rins.