Formula One should deploy the safety car whenever a tractor is used to retrieve a car from the track, Mexican Sergio Perez said on Thursday, as drivers reflected on Jules Bianchi’s horrific crash in Japan last weekend.

Bianchi has been in hospital since the accident at Suzuka, the last medical bulletin issued on Tuesday saying the Frenchman had suffered a traumatic brain injury and was in critical but stable condition.

The 25-year-old Marussia driver, a Ferrari test driver who was an emerging talent, aquaplaned off in rain and poor visibility and crashed into the back of a tractor that was removing a crashed Sauber.

“In the future, when there is a tractor picking up a car, we need a safety car no matter the conditions because there is always a risk,” Force India driver Perez told reporters at the new Russian Grand Prix Circuit.

“You expose the marshals, a lot of people, so we need a safety car if the tractor is on track.

“You could have people run out of brakes, so many factors you never expect, and if the tractor is there it’s a big problem,” added the Mexican. “You don’t want to expose anyone like that. We have to take care of the marshals.”

Formula One’s governing body, the International Automobile Federation (FIA), has opened an enquiry into the accident with a number of questions to be addressed.

How and when tractors are deployed to remove crashed cars has been a concern in Formula One for years and has come under renewed scrutiny.

“For the good of him, for the good of his family, we need to really move forward in terms of safety on what happened to Jules,” said Perez of the popular Bianchi, who was Force India reserve in 2012.

“Hopefully in the future you will never see an accident like this in the whole of Formula One; Being a tractor there and then a car colliding with it cannot happen. We cannot have this.”

Formula One drivers have reacted lukewarmly to suggestions of a closed cockpit, saying a measure of risk is why they like travelling at high speeds.

Several drivers addressed the issue of safety as they spoke ahead of the weekend’s Russian Grand Prix, which comes only one week after the race in Japan.

While not excluding a closed cockpit as an option in the future, some drivers said Thursday they had mixed feelings since Formula One always has been an open-wheel series.

Former champion Fernando Alonso said head injuries were “one part where we are not at the top of safety” and said closed cockpits should be tested.

“We have the technology, we have airplanes, we have had many other samples that they use in a successful way so why not think about it?” Alonso said.

Felipe Massa, the Williams driver who survived a 2009 accident when a flying object that had come off another car fractured his skull, said Bianchi’s accident was atypical because it involved a tractor that happened to be on the spot.

“We cannot do anything when it’s like that,” Massa said. “For sure you think about (the risk), but it doesn’t mean that’s the right thing to do. What I love to do is to race. What I love to do is to be competing. That’s where I feel happiness. That’s where I feel pleasure.”

While Massa agreed with Alonso, Vettel said he had “mixed feelings.”

“We are all old enough to make our own decisions in life ... so it’s our conscious decision if we want to go racing or not. I think we expressed the love that we share for racing, for the thrill, managing the car on the limit,” four-time champion Sebastian Vettel said.

Perez said it would be tough to focus on the racing in Sochi.

“It’s very difficult. I’m here with you guys but all the time your subconscious is thinking about our friend Jules. What happened this Sunday was a big shock for all of us,” he said.

“For everyone who is involved in the F1 paddock it’s a big shock. You always realise that the risk is there but you always think that it cannot happen to you, it will not happen to you,” he continued.

“But when you see that it happen to a guy who was next to you last Sunday and now he’s not with you – he’s in a very difficult situation – that makes you think a lot of things.”

Bianchi’s name remains over the Marussia garage at Sochi, with the team yet to confirm their plans for Sunday’s race.

Files from the Associated Press were used in this report