- France's double Olympic biathlon champion Martin Fourcade's season preparations have been hampered by glandular fever.
The illness, which leaves the sufferer feeling extremely tired, could hinder the 25-year-old's bid to compete in both the biathlon World Cup, which he has won for the past three seasons, and World Cup cross-country events.
"Medical tests carried out recently as a result of Martin's extreme fatigue have revealed the presence of the virus," a French Ski Federation statement read.
"This illness has hampered his early season programme and forced Martin to rest for several weeks."
Fourcade won the 20km individual and 12.5km pursuit titles at the Winter Olympics in Sochi last February.