"We can confirm that Nafi will not be in action during the indoor season and will therefore not participate in the upcoming European Championships and World Indoor Championships," they told the Belga news agency.
The European Indoor Championships are scheduled from March 6th-9th in Apeldoorn, the Netherlands, with the World Indoor Championships following in Nanjing, China, from March 21st-23rd.
The World Athletics Championships will be hosted from September 13th-21st.
Thiam is a three-time European indoor pentathlon champion, winning in 2017, 2021 and 2023. The World Indoor title is the only major honour she has not won. She has competed only once at the event, in 2014 in Poland, where she finished eighth in the high jump.
Last year, the Belgian won gold in Paris for a third successive Olympic triumph. She also has two world titles but did not compete at the last championships in Budapest in 2023 because of an Achilles tendon injury.