Peru striker Guerrero has dengue fever
The former Bayern Munich star missed his side's league clash with Pronte Preta at the weekend with a fever and was sent to hospital for tests.
Guerrero's diagnosis was confirmed on Tuesday, but it is hoped he could return to training in around two weeks.
According to the World Health Organisation (WHO), dengue fever is a mosquito-borne viral infection which "causes flu-like illness, and occasionally develops into a potentially lethal complication called severe dengue".
The global incidence of Dengue has risen dramatically in recent years and is most commonly found in tropical and sub-tropical climates, in urban and semi-urban areas.