Still trying to cope with Bianchi's accident, some of the leading drivers said Thursday they had to be professional and focus on the race, despite the "grey cloud" over this weekend's event in Sochi.
"All our thought are with Jules," Ferrari driver and former champion Fernando Alonso said. "I have a huge respect for our sport but when big accidents happen, there are no words to describe the feeling.
"It's going to be emotionally very difficult, we will race for him, in our minds we are with him, praying."
Bianchi, who was part of Ferrari's young drivers program, sustained a severe head injury Sunday when his Marussia car slid off the track in rainy conditions on the Suzuka circuit during the Japan Grand Prix and ploughed into a crane picking up the Sauber of Adrian Sutil, who had crashed out at the same spot one round earlier.
The French driver remains in a Japanese hospital in critical but stable condition.
Sutil, who witnessed Bianchi's accident, would not get into details, calling it "shocking for everyone."
"We have to pray, that's all we can do. Although there is a grey cloud over us, we have to try to be professional and race for him," Sutil said.
Felipe Massa, who survived a life-threatening accident in 2009, said the race in Japan was "the worst race of my life."
"Since I did not remember my accident," Massa said of 2009 Hungarian Grand Prix when he was hit in the head by a flying object that had come off another car and fractured his skull.
"It's been a difficult week for all of us. Tomorrow we should do the best we can, for him and his family," Massa said, referring to Friday's start of the racing weekend.
McLaren's Jenson Button said it was a "very horrible feeling knowing what your fellow driver is going through."
Torro Rosso's Daniil Kvyat said he had "mixed thoughts" although he will be at the centre of attention in his inaugural home Grand Prix.
"All drivers have one wish, to hear positive, better news, that he will recover, that's all that matters," Kvyat said.
Four-time champion and Red Bull driver Sebastian Vettel said he though Bianchi's accident was due to a set of unfortunate circumstances.
The rainy, fading-light conditions in Suzuka left "a very small margin for error and it was too small for Jules," Vettel said.