The striker, known as Bomber Harris, was Millwall's top scorer with 138 goals. In 2011 he signed for Southend and retired in June 2013.
How and when were you diagnosed?
"It was in June 2001. I'd just completed a great season with Millwall. We'd won the old second division championship and I'd finished as top scorer with 28 goals. There was speculation that I might be moving to a Premiership club and everything was fantastic. Then one day I was watching television with my hands resting in my shorts, as blokes tend to do. And as I felt my testicles, I thought, 'This doesn't feel right.' One was bigger than the other."
Find out about the symptoms of testicular cancer.
What happened next?
"The next morning I rang the club doctor and he told me to come straight in. He then sent me to hospital to have an ultrasound test. I got dressed and a doctor gave me the diagnosis. I had testicular cancer."
How did you feel when the doctor broke the news?
"A million things went through my mind in a split second. My first question was, 'Will I live?' and the second was, 'Will I be able to play football again?' At that stage, the doctor couldn't give a definitive answer. I just kept asking myself: 'I'm a fit and healthy person, so how could this happen to me?' I was quickly taken for a CT scan to see if the cancer had spread further around my body, and then I had chest X-rays to check my lungs. Fortunately, the cancer hadn't spread."
How did you break the news to your loved ones?
"That was tough. Being told I had cancer was obviously very hard, but telling other people was extremely upsetting. I think it was harder for some of my family to live with than it was for me. My mother and sister found it particularly difficult. I had to be strong for them."
What treatment did you have?
"I had an operation, which was quite straightforward, and afterwards I felt OK. Following the operation, I was lucky enough to have radiotherapy rather than chemotherapy, so I didn't lose my hair. Looking from the outside, you wouldn't have been able to tell that I was ill. But if I hadn't caught my cancer early, it could have been a lot worse for me. It could have been fatal."
How did the cancer and treatment affect your love life?
"Well, fertility was one of my big worries. Chemotherapy and radiotherapy can stop you having children, so in between the operation and the radiotherapy, I had some sperm stored just in case. However, in the six days between the operation and the start of the radiotherapy treatment, my wife and I had sex twice and my wife conceived during that time. So losing one testicle wasn't the end of the world because the other one took over. Since the radiotherapy, we've had a second child, so I'm obviously still fertile."
How quickly did you return to playing football?
"I was diagnosed in July 2001 and was back playing football in November. It turned out that I'd rushed back a bit too quickly, so I needed another rest and then I started again on January 1 2002. Although the cancer has given me a new perspective on life, I still love my football."
What is your advice to anyone who is worried about testicular cancer?
"If you think anything might be wrong, just go to see your GP. That's what they're there for. I understand that some men don't want to go to a doctor for any reason, let alone such a serious one that involves their private parts. But this is your life we're talking about. It takes a bigger man to go and speak to his doctor than it does to pretend nothing is wrong. So just go."
healthtalk.org has videos and interviews with men about their experiences of testicular cancer.