Froome sparked an AAF in the final week of the 2017 Vuelta a España as he fought for overall victory. Twice the permitted 1,000ng/ml level of salbutamol was found in his urine and he could now lose his Grand Tour win and face a ban from the sport. Because salbutamol is a 'specified' substance on WADA's prohibited list, Froome has not been provisionally suspended and has set the Giro d'Italia and Tour de France as his major goals of 2018.
To avoid a conviction, Froome and his legal team must convince the anti-doping authorities that he did not exceed permitted dosage and that his sample was skewed by other factors, such as dehydration.
Team Sky manager Dave Brailsford suggested that "there are complex medical and physiological issues which affect the metabolism and excretion of salbutamol."
He added, "I have the utmost confidence that Chris followed the medical guidance in managing his asthma symptoms, staying within the permissible dose for salbutamol."
Earlier on Thursday, former Tour de France winner Greg LeMond criticized Froome, labelling his expected defence as "ridiculous".
"That is the most ridiculous excuse I have ever heard. If this is what he claims, then it's simple, he broke the rules and should be punished accordingly."
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Van der Poel was similarly blunt.
"It's very stupid, I can't help saying that. Maybe I'm a bit too blunt for saying it like this. Maybe asthma patients will understand the case better, but cycling and all sports in general are for healthy people," the young Dutchman said during an interview on the Dutch television show AvroTros (OneToday) and reported widely in Belgium and the Netherlands.
"A suspension, that's what I think. For me it's a positive test. If the limit is 1,000 and he's up to 2,000, then there's not much discussion needed. That's a positive test."
Salbutamol's properties as a bronchodilator mean that it is on the World Anti-Doping Agency (WADA) prohibited list, but it is permitted for therapeutic reasons. An athlete faces a potential anti-doping sanction if a urine sample contains a level of salbutamol that exceeds 1,000ng/ml. Above certain levels salbutamol is believed to have an anabolic effect and increase performance.
Van der Poel suggested that limits on certain drugs mean the rules are open to abuse.
"The UCI allows that abuse, is possible. If you state that it's not allowed, then it will not happen," he said.
"Now, they're saying that it is allowed up towards a certain amount. Then you just know that some people will try to get up to that height; the ideal height. I think the UCI is partly to blame about that."
Van der Poel was interviewed while driving home after the recent Namur World Cup cyclo-cross race. He said he had no problem talking about the sport's problem with doping even if it is often a taboo subject in traditional cycling countries such as Belgium and the Netherlands.
"I don't have much problems with that. If we're open then the best thing to do is to talk about it. Now I can say that I don't do it and that's the case, but those who did it always said that too," he said.
When it was suggested that people would think he was simply lying, he replied: "That's what I mean. Then you get reactions like that. So, there's no use for me saying it anymore. We reached the point that people don't believe you anymore and that sucks."
Van der Poel has dominated this winter's cyclo-cross racing, regularly beating main rival and current world champion Wout Van Aert. He refuted that his dominance has somehow made cyclo-cross boring.
"Well, if Barcelona plays a poor side, then it can be beautiful to watch too. That's probably how you've got to look at it," he suggested.
