Mathieu Van Der Poel will miss his world title defense in the US later this month after a back injury put an end to his cyclocross season. It is unclear if the injury will affect his road season in Alpecin-Phoenix or his spring classics campaign.

The Dutchman has been suffering from a swollen disc since the middle of last year and has been advised to rest to allow it to heal completely.

Van der Pol had to delay the start of the 2021-2022 cyclocross campaign due to another knee injury and only competed twice before his back injury flared up and forced him to stop racing.

The past week has been filled with speculation about how long it would take the four-time world champion to recover, but on Wednesday he and his team confirmed that the problem is serious enough to erase the rest of his world championship and winter cyclocross ambitions.

"I can't say too much. The pain in my back has prevented me from reaching the level I want after the Tour. I want to put that behind me," van der Pol said.

"The only solution is a longer rest period. So it would be foolish to interrupt this period again to try to compete in the World Championships. We all agree on that, we have competed in the CX World Championships 10 times in a row and it is really frustrating not to be able to defend our title in the US.

Van der Pol, who suffered a knee injury in a "stupid" training crash in November, made a late return to cyclocross but was stronger than expected, finishing second behind Wout van Aert in the Dendermonde World Cup. However, he was unable to finish the Heusden-Zolder the following day and was soon diagnosed with a swollen disc in his back.

The physical therapist related the problem to van der Pol's efforts over the years in various disciplines, referring to "the attacks he has made on his body," and stressed that only rest could solve the problem. His father, Adri van der Poel, also urged him to rest for a while, and the Alpecin Phoenix team came to the same conclusion.

"We want to optimize the healing process, but with the pressure of competing in the World Championships in Fayetteville, it is not possible. We have therefore decided to end his cyclocross campaign," team managers Christophe and Philippe Rudhoeft said in a joint statement.

"There are no medical reports. Mathieu has kept his prescribed rest and his injury is being monitored by the medical staff and specialists.

The question now is when Van der Pol will return to racing and regain full strength, and neither he nor the team has an answer.

Now that the cross season has been canceled, his attention has turned to the road, with his first major goal being the spring classics. But while Wednesday's news appears to be a sign of his efforts to protect his spring, there is currently no guarantee that he will be able to compete in Milan-San Remo, Tour de Flanders, or Paris-Roubaix.

"I am not worried about the future of my career, but not knowing how long this rest period will last is of course frustrating right now," van der Pol said. But of course it's frustrating right now that we don't know how long this rest period will last. Until then, I will do what I can."

The Roodhoft brothers added that they cannot put a deadline on their injuries and rehabilitation at this time.

"Speculation that it will take weeks or months is unfounded. It is currently impossible to predict how long it will take for the swelling to disappear. The doctors treating him are in agreement that the swelling will go away with rest. For Mathieu and the team, that is the most important thing.

"We will probably start the road season after the injury is healed and we are properly prepared. At this point, it makes no sense to specify that date. Only when that happens will we do so."