Niki Terpstra was left in intensive care after a high-speed training crash.
The Classics star was training behind the scooter when geese walked out into his path, causing him to fall.
Terpstra, 36, was taken to hospital with a collapsed lung, a concussion, broken ribs and a broken collarbone, according to his wife Ramona.
She said on Instagram: “He’s not in mortal danger, but will need time to recover from this.
“He’s in the hospital and will have to stay here for a few more days.”
She then told Belgian newspaper Het Nieuwsblad: “Inn an effort to avoid the crash he dived at high speed, went off the road and flew into a deep ditch through the embankment where he landed with his chest against a boulder.”
Terpstra was taken to hospital by air ambulance after he crashed on the embankment between Lelystad and Enkhuizen.
His Total Direct Energie team said on Twitter: “After a heavy fall in training today, our leader Niki Terpstra was rushed to the hospital.
“Despite severe injuries, he is conscious and out of danger. The whole team wishes to support him.
“Courage Niki, we are thinking of you.”
Terpstra has suffered a number of nasty crashes over last two seasons, having suffered a severe concussion in the 2019 Tour of Flanders and then being forced to skip Paris-Roubaix.
He was back on the bike in time for the Tour de France, but was forced to abandon on stage 11 after he crashed on the road from Albi to Toulouse and suffered a broken collarbone.
Terpstra had a busy 2020 season before all racing was suspended due to coronavirus, as he raced the Saudi Tour, Ruta del Sol, Opening Weekend and Paris-Nice.
The Paris-Roubaix and Tour of Flanders winner has been with Total Direct Energie for two seasons, having left Quick-Step at the end of 2018 after eight years.