adminThe condition was diagnosed following tests after the Bulgaria international, 32, developed a fever following last Saturday’s 3-0 defeat at Arsenal.
“We expect to learn more about the situation in due course,” Villa said.
“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.”
A club statement added: “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.”
Petrov joined Villa from Celtic for £6.5m in 2006 and has scored 12 goals in 219 appearances.
He played the full 90 minutes at Emirates Stadium last Saturday, his 30th game of the season.
Celtic manager Neil Lennon, a friend and former team-mate of Petrov, said: “We are all absolutely devastated to hear this news.
“As a member of the Celtic family, it is important for Stiliyan to know that he has our unequivocal support in battling against this disease.
“Knowing Stiliyan as I do, and the many obstacles he has overcome in his life to get to the peak of his career, he will overcome this one too.
“On behalf of the players and the backroom staff we send our support and best wishes to Stiliyan, Paulina and the family.
“We are there for them all and they will never walk alone.”
Celtic chief executive Peter Lawwell added: “This is terrible news and our support and prayers go to Stiliyan, Paulina and their family at this very difficult time.
“Stiliyan was an exceptional player for Celtic and helped to bring incredible success here during the seven years he spent at the club.
“He was also one of the most popular players here, not only within the club but with all our supporters and I know that they, too will want to pass on their support and best wishes to Stiliyan and his family.” —BBC.
Online Reporter