Petrov, 32, who is due to start treatment on Monday said football would have "to take a back seat for a while".
Gary LinekerBBC Sport presenter
"My eldest son George had acute myeloid leukaemia when he was a tiny baby, he is now 20 and doing very well. He is a mini-miracle in many ways.
"In both Stiliyan Petrov's case and with Fabrice Muamba a few weeks ago, the football family has united from all parts of the game and all parts of the world. It is very comforting to see that.
"Through George's illness we had incredible support from right over the world. We had sacks of mail arriving for us every day. The thing that really helped was hearing stories of people who had been in similar circumstances and had come through it.
"What you need is the encouragement to know that it gets better. Petrov is clearly a positive person, you saw him at the game today, and that is the most important thing; to know that the support is there and that people are behind you."
In the 19th minute of the game, chosen to match Petrov's shirt number, the whole ground and both benches stood up in applause and chanted his name.
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