Dennis Potter, in his final television interview before his death from cancer, said that to live in the present moment is something none of us really appreciates, and that just to look out of his window and see trees and fields filled him with incredible joy.

"If people could only see the 'nowness' of everything, and live in the present tense like I now do, then boy, is it worth celebrating," the playwright said.

Sandy Jardine can relate to these sentiments. This Rangers legend, one of the finest defenders Scotland has produced, has cancer of the throat and liver and this weekend is at the midway point of a gruelling schedule of radiotherapy.

Three months ago, after an operation in which four-fifths of his liver was removed, he lingered right on the edge for 10 days in intensive care.

"I could have died – maybe I should have died – but somehow I pulled through," Jardine says. "You don't appreciate things when you are well. Having this illness has made me think a lot more about myself, my family, my life."

At 64, like any fit and healthy human being, the last thing Jardine expected was to be dealt this massive blow. In fact, cancer afflicts a high proportion of us – around one in three – but that statistic, and the knowledge of others having it, doesn't equip you for the day when you receive the dreaded news.

"I was at Murray Park one Saturday morning and I said to the Rangers doc [Paul Jackson], 'I've got a bit of a sore throat'. He took a look at me and said, 'yes, Sandy, and your glands are up as well.' He decided he wanted a specialist to have a closer look at me, and that was when the bad news was delivered.

"A specialist did some tests and said, 'you have cancerous cells'. Further scans showed a shadow in my liver. Eventually they found three separate growths down there. I just felt disbelief. I was completely shocked. I've never smoked, only drink occasionally, and I've led a very healthy lifestyle. I found it all pretty hard to take. I thought I was Mr Invincible. But you just have to snap out of it and get on with the treatment."

Jardine is now five months into his battle, and is making good progress. But the journey has been rocky and debilitating. With cancer of the throat, plus a secondary cancer of the liver, doctors had to decide which to tackle first.

They operated on Jardine's liver but he contracted an infection, which required the surgeons to "go back in". Finally, with that negotiated in mid-November, Jardine then faced 30 blasts of radiotherapy to his throat.

"I've had 14 doses so far – 16 still to go," he says stoically. "It was scary at first. Mine lasted 10 minutes each time. You lie there, they put a mask over your face and you feel locked in, you feel pretty daunted.

"Various people had told me what to expect but I was still apprehensive. 'Don't move,' they told me, or else the target wouldn't be hit. I'm lying thinking, 'I've hardly been in a hospital in my life, I've never smoked, I'm not a drinker – and now this?' It was quite a shock to the system."

Never mind a fit man being struck down like this, the irony of the timing of Jardine's ill-health was not lost on many. As his beloved Rangers lurched into liquidation, he emerged as a bugle-blower in the club's recovery, rousing the fans with his presence. Jardine had taken to making upbeat pronouncements via the Ibrox PA system – something that really isn't him – and was becoming lionised by the club's battered supporters. Then, all of a sudden, he was laid low.

"After two operations I was in bed for six weeks and couldn't walk when I was finally allowed up; my legs just wouldn't work," he said. "I suffered panic attacks, when I lost control of my breathing, because I couldn't believe that I wouldn't walk again. I've had to learn how to do that all over again."

My abiding memory of the man I'm speaking to is not the courteous, middle-aged figure seen around Murray Park or Ibrox. I still think of Sandy Jardine as the thoughtful, adventurous Rangers full-back of the 1970s, a defender whom wingers dreaded facing and who knew how to defend and when to attack.

The phrase "the over-lapping full-back" was a verbal coinage of the 1970s, and in Scotland Sandy Jardine was the very embodiment of it. In Jardine and Danny McGrain, his contemporary and foe at Celtic, Scotland were deemed to have one of the best "full-back partnerships" in Europe.

Between radiotherapy sessions, Jardine tries to walk at least half-a-mile each day. It has given him plenty of thinking time. "I've been humbled by the good wishes of people. Everyone around Rangers – the staff, the fans, everyone – has been magnificent towards me. When I went to that game at Ibrox a few weeks back, and the crowd were acknowledging me and clapping me . . . well, I found it pretty emotional.

"When you work for Rangers, it becomes all-consuming. Rangers have been a big part of my life but this has put everything in context. The people around the club have been fantastic. But I've had good wishes from all over – from guys like Danny [McGrain] at Celtic. Peter Lawwell also wrote me a lovely letter. I've been incredibly touched by people's support, it has really lifted me."

Jardine was once a cog in a brilliant Rangers team. But these days he has grown to appreciate another form of "teamwork", from his fellow cancer sufferers. "I still get down a wee bit, I have my bad days. But then you meet people in the hospital who are going through the same battle you are, and they tell you their stories. You build up a kind of comradeship, that's the only way I can describe it. You feel like you're not the only one, that you're all in the same boat.

"Like I said, you don't appreciate things when you are well. I'd hardly been in hospital before and I'd always felt fit and healthy. I felt like nothing could put me down. Now, here I am with cancer."

The future remains uncertain but Jardine can take comfort from the fact many people fight cancer successfully and get back to a relatively normal life. He is slowly and steadily taking one day at a time. "I'll take the doctors' advice," he says.

"Also, and please make sure you quote me saying this . . . the doctors and nurses of the NHS have been wonderful to me. The NHS has its critics but I have learned how caring and talented these people are. But for them, I might not be here."

Everyone in Scottish football – especially Rangers fans – will relish the day a fit and well Sandy Jardine resumes normal life. He might also be able to testify to us just how wonderful life is.