Barcelona have confirmed defender Eric Abidal and midfielder Yaya Toure have contracted swine flu.
The Spanish league leaders said that Abidal was tested for the virus after feeling unwell and developing a fever, with club doctors confirming the 30-year-old had caught the illness.
Midfielder Toure later showed similar symptoms and underwent similar tests, but has now officially been diagnosed.
The pair have been ruled out of Saturday's clash with Athletic Bilbao, as officials at the club put in precautionary measures to stop the virus spreading.
A statement from Barcelona read: "Eric Abidal and Toure Yaya have viral-like symptoms with fever and general discomfort.
"Relevant tests have been carried out on both players and these have confirmed that it is swine flu.
"This Friday at midday the club's medical services informed that Eric Abidal
had swine flu and in the afternoon the tests carried out confirmed that Toure
Yaya was also suffering from it.
"The medical services are working following the protocols established by the
health department isolating the players, carrying out symptomatic treatment and giving appropriate hygienic measures."