Stiliyan Petrov leukaemia battle: Aston Villa captain retires
Aston Villa captain Stiliyan Petrov has retired from football as he continues his fight against acute leukaemia.
The Bulgarian midfielder, 33, was diagnosed with the condition in March 2012 but is now in remission.
"It is with a heavy heart that I am announcing my retirement," he said.
"The emotions are overwhelming, but the continued support of family, friends and the great people I have come to know will make it easier for me to move on from the only life I've ever known."
Stiliyan Petrov's career
- CSKA Sofia: August 1998 - July 1999
- Celtic: July 1999 - August 2006
- Aston Villa: August 2006 - May 2013
He made 218 appearances for Villa in all competitions and earned 92 caps for Bulgaria, but will now focus on setting up a foundation to help leukaemia sufferers.
He said in a statement on Aston Villa's official website: "That I am ready to embrace new challenges will make this process much easier.
"I remember when I was a young player at CSKA Sofia and the good life was all I was interested in. Celtic came in for me and I moved to Glasgow, to another country, to a new world. I didn't speak the language and I thought it would never happen for me. I knew nobody.
"Fortunately, I met people who helped me to turn my life around. I came to know great team-mates who showed me the proper way, the way I had to be if I was going to be a serious professional and compete at a high level.
"I came to appreciate so much the opportunity to work with that level of professional people because it made me something like them. At Celtic Football Club and at Aston Villa Football Club I was privileged to live a life competing at a high level and playing the game I love, supported by the most passionate fans."
It was revealed in August that Petrov was in remission after four months of chemotherapy. He said he would be "on the softer treatment, which is two years on tablets" and last month said he felt lucky to be alive.
The condition was diagnosed after he developed a fever following a 3-0 defeat at Arsenal in March 2012.
"Then something crazy happened, something I thought was just a cold but turned out to be something more serious, something life-changing," he said.
What is leukaemia?
Leukaemia is cancer of the white blood cells. Symptoms include pale skin, tiredness, breathlessness and susceptibility to infection. Acute leukaemia means the condition progresses aggressively and needs immediate treatment.
On average 2,500 adults are diagnosed with acute leukaemia in the UK each year, according to Leukaemia & Lymphoma Research.
"I played 90 minutes for Villa against Arsenal at the Emirates and I felt fatigued, not myself at all. But I thought it was nothing serious. The diagnosis was a complete shock.
"Since being diagnosed with acute leukaemia, I have come to understand and appreciate the way in which this disease impacts the lives of so many people.
"I can help and I want to help and, in setting up a foundation to help address the issues involved when people are diagnosed with this illness, I hope to make a difference.
"For the life I've lived in football, I will always be incredibly grateful. For the opportunity this crazy thing that happened in my life has given me, I also feel grateful in a strange kind of way.
"This crazy thing, somehow, has touched people and I want to try to channel this in a positive way. This will be the greatest challenge of my life."