Terry doesn't enjoy the greatest reputation amongst a section of England's press, but Petrov has only good words for the former Three Lions captain.
He revealed to the Sunday Mirror: "Before I was ill I knew John only from shaking hands before kick-off in matches, and as a fierce competitor.
"We had also met and talked at the meetings the Premier League hold for captains before the start of each season.
"But from the moment the news came out about my illness he was one of the first to get in touch and he has carried on being supportive ever since. He doesn't always have an easy time with the fans, but I have seen a very different man to that image.
"He has gone out of his way to encourage me at different times - always sending messages and texts while I was going through treatment, even though sometimes it might have been a month before I felt strong enough to return them.
"When I was planning this game he was the first to sign up. I rang and asked if he could take part and he just said: 'Tell me when and I'll be there. Who wouldn't want to play in the atmosphere of a sold-out Celtic Park?'"
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