Aston Villa have announced that captain Stiliyan Petrov has been diagnosed with acute leukemia.
A club statement read: "Stiliyan developed a fever following the Arsenal game last Saturday and subsequently underwent tests conducted by Dr Ian McGuinness."
"Haematology experts confirmed the diagnosis today."
"We expect to learn more about Stiliyan's situation in due course and we have moved quickly to support him and his family."
"During this time we ask that Stiliyan's privacy is placed ahead of all inquiries and trust that we will share information as we receive it."
"Stiliyan is cherished by many and he will get from Villa every ounce of love and support that we have to help bring this to a positive conclusion."
Petrov joined Villa from Celtic in August 2006 and has made 185 Premier League appearances for the club.
The 32-year-old is also the captain of the Bulgarian national team, and has made over 100 appearances for his country.