Van der Poel finished a strong second to Wout van Aert in his 'cross season debut in Dendermonde on Sunday, but after a fast start in Zolder he quickly faded from the leading group and dropped out of the race after 45 minutes.
Alpecin-Fenix said that medical examinations showed "a swelling on an intervertebral disc" and said it is unclear when he can resume training and racing. He will not be at the start of the Azencross in Loenhout on Thursday and will also miss the UCI Cyclo-cross World Cup in Hulst on January 2.
Van der Poel is due to have another doctor's visit "immediately after New Year's" which will determine what his schedule will be next month.
"Obviously this is a setback, but there is no reason for panic," Alpecin-Fenix Manager Christoph Roodhooft said. "The doctors guarantee us a full recovery and that is a priority at the moment. Even if that would lead to adjusting the ambitions for the cyclo-cross World Championships. In the short term, that would be a shame, but 2022 offers a lot of sporting challenges for which physical readiness is a first condition."
Van der Poel struggled with back pain for much of the season, with reports attributing the injury to switching between his road bike and mountain bike as he balanced an ambitious road campaign with preparation for the Olympic Games. After finishing second at Tour of Flanders, he raced two MTB World Cups, then returned to the road for the Tour de Suisse and Tour de France, where he won the second stage and wore the yellow jersey for six days before dropping out to shift gears toward Tokyo.
He crashed hard in the men's cross-country medal event and then left an August altitude training camp early and delayed his return to the road because of the back injury, but healed up in time to place third at Paris-Roubaix before ending his season. The flare-up is another setback for the Dutchman, who said, "It's frustrating, but it is what it is."
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"The problem has been there for some time, and I am somewhat relieved that there is an identifiable cause that can be remedied with extra rest and treatment. Everyone knows that the World Championships in the United States is the first big goal of 2022, but it is certainly not the only or the last one.
"I want to fully recover first, without time pressure so that I can use my full possibilities. I will therefore only resume competition when I'm completely ready. If I make it to the World Championships, that's all the better. If it's not the case, I'll be looking forward to the spring season on the road."
Laura Weislo is a Cyclingnews veteran of 20 years. Having joined in 2006, Laura extensively covered the Operacion Puerto doping scandal, the years-long conflict between the UCI and the Tour de France organisers ASO over the creation of the WorldTour, and the downfall of Lance Armstrong and his lifetime ban for doping. As Managing Editor, Laura coordinates coverage for North American events and global news.
