Carlos Sainz could yet start the Russian GP if he is passed fit by the FIA on Sunday morning, and the Toro Rosso management agrees that he is ready to get back in the car.
Sainz was supposed to be spending tonight in hospital as a precaution, but the team says he has now been released. The FIA stewards have already said that the Spaniard will be allowed to start despite not participating in qualifying, and Toro Rosso is building up a car for him.
“As you can see I am fine,” he said in a video sent from hospital. “My back and my neck are just a bit sore from the accident, but I’m totally ready. Hopefully tomorrow I will wake up in a good shape and maybe I can try and race – this is definitely the intention! Obviously we need to be cautious… I’ve always been conscious.
“As soon as the accident happened I tried to talk to the team on the radio, but it wasn’t working and those must have been some scary moments… I’d like to thank everyone for their support, it’s really nice to receive all your messages at a moment like this one! I hope to see you all tomorrow out there!”
Meanwhile team boss Franz Tost explained that the crash may have been caused when Sainz was caught out by a change of brake balance.
“I hope he will have a good night’s sleep and tomorrow morning he will have to go through the FIA medical checks to decide if he will be able to take part in tomorrow’s race. Now, just to clarify what happened, prior to the accident, Carlos had completed a long-run on the Option tyre, before changing to the Prime to do two further laps.
“On Primes the grip level is lower. In addition he had changed the brake [balance] on the steering wheel, which meant he had more braking rearwards. A combination of these two factors might have been the cause of the rears locking, which made the car uncontrollable.”
Adam Cooper's F1 Blog 
Great news & I hope he gets to race. The accident looked dramatic, and the fact that he was trapped in the car is a worry but the barriers did their job. If something is going to absorb the energy of the impact then it is a good sign that it has moved so much. Far better for the driver than the car bouncing off the barrier.
I know a lot was said on the TV about the barrier ending up on top of the car but it is relatively lightweight and very flexible. The scarier thing for me was the prospect of that tethered front left wheel detaching and hitting him at some point.
If there is one thing that maybe could be changed for the future is to have some anchor points on the tecpro barriers to make it easier for straps to be attached to pull / lift them out of the way in incidents like this.
Good point on making removal easier. But I think they are heavier than they look, and contact with a driver’s helmet given the forces involved would potentially be a very serious matter.