Dutch rider Fabio Jakobsen has had facial surgery and doctors will try to wake him from a coma later on Thursday, says his Deceuninck-QuickStep team.
Jakobsen remains stable, having been taken to hospital on Wednesday following a high-speed crash on stage one of the Tour of Poland.
Dylan Groenewegen drifted across the road before he and compatriot Jakobsen collided close to the finish line.
Jakobsen, 23, hit the barriers before striking an official stood by the line.
“His condition is very severe. There is a danger to his life,” said race doctor Barbara Jerschina on Wednesday.
“Unfortunately, it is quite a serious injury to the head and brain. He has lost a lot of blood. He is very strong. I hope he will survive.”
Deceuninck-QuickStep said on Wednesday that initial tests “didn’t reveal brain or spinal injury”.
“Fabio Jakobsen’s situation is serious but at the moment he is stable,” read a team statement.
“Because of the gravity of his multiple injuries, he is still kept in a comatose condition and has to remain closely monitored in the following days.”
Jumbo-Visma sprinter Groenewegen, who was named as the stage winner before being disqualified, and several other riders also fell after crossing the line.
Jerschina said the race official struck in the incident suffered head and spinal injuries but was speaking when he was taken to hospital.
Cycling’s governing body UCI said it “strongly condemns the dangerous behaviour of Groenewegen”.
A statement read: “The UCI, which considers the behaviour unacceptable, immediately referred the matter to the disciplinary commission to request the imposition of sanctions commensurate with the seriousness of the facts.”
Jumbo-Visma said: “Our thoughts go out to Fabio Jakobsen and other people involved in today’s terrible crash in the Tour of Poland – crashes like these should not happen.
“We offer our sincere apologies and we will discuss internally what has happened before we may make any further statement.”
The podium ceremony was cancelled and the results of the 195.8km stage from Stadion Slaski have not been released.