Van der Breggen, who is the reigning world champion after winning in 2020 at Imola, won't be defending her title on the 30.3 kilometre course that finishes in Bruges. The Netherlands also won't be able to call up a replacement for the 31-year-old, because she had her own personal starting place as the defending world champion outside of the Netherlands quota.
The Netherlands will still have a strong trio of riders for the time trial though, with Olympic TT champion and two -time world TT champion Annemiek van Vleuten, recent European road race champion Ellen van Dijk and Riejanne Markus all included for the event.
Van der Breggen withdrew from the European Championships last week after finishing 58th place in the general classification at the Challenge by La Vuelta, saying that she wasn't at her 'normal level', which she repeated as her reason for withdrawing from the World Championships time trial.
"I have no idea why I am not reaching my level at the moment," said Van der Breggen. "We will conduct several investigations in the coming days. On the basis of that, I determine my further program this year."
Sports director at SD Worx, Danny Stam, also suggested that she is suffering from a lack of energy, which impacted her decision to withdraw.
"Anna had too much on her plate and sometimes the bucket overflows," said Stam. "We have seen the results of her blood values and her vessel with energy is somewhat empty, so she has to take it easy. The time trial is a very specific part and takes a lot of energy."
The World Championships road race is on Saturday 25 September, broadcast on SBS VICELAND, with van der Breggen's participation still up in the air. Dutch coach Loes Gunnewijk has said van der Breggen will make the choice whether she will ride the race as defending champion.
"Anna has her own starting place at the World Championships," said Gunnewijk, "as far as I'm concerned, she can also decide at the last minute about her participation."
The 2021 UCI Road World Championships will be broadcast to Australian viewers on SBS, with all events live-streaming on SBS OnDemand, and the elite women's and men's road races live on SBS VICELAND.