After the spectacular crash with a spectator, Daniel Oss also has to give up at the Tour de France.
His TotalEnergies team announced on Thursday night that further investigations had revealed a cervical fracture.
"He's not allowed to move for a few weeks and has to leave the tour," the statement said.
The accident on the third cobblestone sector of stage five had already forced Austrian Michael Gogl to retire due to a broken pelvis and collarbone.
According to his Alpecin-Deceuninck team, Gogl now needs an operation.
"Guys, please stay off the road"
Oss had been riding on the edge of the cobblestones in the sector, hit his head on an unwary fan and fell.
At high speed, Gogl, who was racing up behind him, could no longer avoid it and flew over Oss' wheel.
The Bora-hansgrohe driver Danny van Poppel, who was also involved in the fall, can continue the tour.
"Guys, please stay off the road," wrote professional cyclist Simon Geschke on Twitter.
There was a serious fall on the tour last year when the German Tony Martin crashed into a spectator's cardboard sign held on the street, with which she wanted to greet her grandparents.
Cycling star Primoz Roglic also fell on the fifth stage, but without the impact of spectators.
The Slovenian dislocated his shoulder - and then put it back in place himself, as the 32-year-old confirmed after the 153.7-kilometer drive to the Arenberg forest.
"I couldn't straighten it right away, so I had to sit in a spectator's chair.
I have a special technique and that's how I put it back together," said Roglic in a TV interview.
Roglic wants to continue the tour.
However, his chances of the first overall victory are now very slim.
The 32-year-old lost more than two minutes to defending champion Tadej Pogacar in the fall.
As a result, Roglic should provide help for the rest of the tour for the Dane Jonas Vingegaard, who is only 21 seconds behind Pogacar.