At 43 years old, and 14 years since his sole major championship win, and even after all the pain and disintegration, David Duval still believes in his ability.

"A lot of bad things have happened to me, but I can still hit some wonderful golf shots," he says. "I feel there is still something there within me."

It is quite poignant speaking to Duval - for a brief period the hottest sportsman on the planet - and seeing him limping along like a bird with a broken wing. Back in 2001 at Lytham, when Duval won The Open, no-one would have believed it would be his only major triumph, let alone his last tournament win.

His hot streak in his prime was breath-taking. Between October 1997 and April 1999 Duval won 11 out of 34 tournaments he entered. He was an erupting volcano, consuming everything in his path. In April 1999 a Sports Illustrated front cover pictured him wearing his trademark wraparound sunglasses, blowing smoke off a 5-iron, beneath the headline: "David Duval Is On Fire".

It would soon - and abruptly - stop. Injuries of every kind started to invade him, and his 2001 Open win was the beginning of the end. Unbelievably, Duval would be finished as a top golfer at the age of 29.

"We all have thoughts about wishing things could have gone a different way in our lives," he says. "More than anything, my curiosity revolves around what I might have continued to achieve, had I not had my injuries. But I suffered about 12 different injuries in all: my back, my knees, my ankle, everything. My body just couldn't cope.

"A lot of bad things started happening to me which made it difficult to play golf consistently. You do start to think, 'what might have been, had I stayed healthy?' But it's neither here nor there now - I didn't. My body broke down."

With his career blossoming, it suddenly withered. In fact, it was in Scotland that Duval's woes took hold. Fifteen summers ago, even when his greatest moment was still ahead of him, he knew something was going wrong.

"It was right after the 2000 Open over here, at St Andrews," he says. "I'd hurt my back at Loch Lomond the week before, and something flared up. I played the 2000 Open all but crippled. After that, I laid out on the floor for six straight weeks. So, while I won the Open in 2001, my troubles actually started the year before that, here in Scotland.

"My blight stemmed from those injuries. My back got really bad and I started making these compensatory swing-adjustments. That was the start of it all. My game suffered.

"I developed one thing that became very detrimental to me - I get my hands high, down through the ball, and basically I get underneath the shot. It is an awful thing - every now again you can hit a good shot if you time it right - but in general you can't play good golf that way."

These days Duval plays next to no golf - this week's Open is only his fifth tournament this year. In the USA he has developed a reputation as an engaging, sometimes quirky TV analyst, with his career long since winding down. But, when I venture any pity for his abrupt career decline, he wants none of it.

"Hey, listen, I couldn't be happier off the golf course," says Duval. "I've got a wonderful wife, some wonderful kids, a wonderful family. So, yeah, I wish the other part - my career part - could have worked out better. But it wasn't to be.

"I don't lose sleep over it. There is nothing I could have done about it. I wasn't doing silly things that caused my injuries - it was just wear and tear. I could no longer compete."

Last week at Gullane Duval shot 77 and 75, missing yet another cut, but he was keen to point out that, in between disastrous opening and closing holes in his first round, he was one-under-par for 16 holes. In the face of everything his optimism persists, just as it did in 2009 when, out of nowhere, Duval finished tied-2nd in the US Open.

"I'm quite pleased with how I'm playing," he says. "With the exception of a few holes, I played nicely at Gullane. A lot of the time, save for some crappy tee-shots, I'm still in control of the ball.

"I've hardly played this year, so there is a competitive rust about me. It comes from not competing week in, week out. It gets more difficult.

"It feels strange to say it, but this will be my fifth Open at St Andrews, and I'm looking forward to it. If I could eliminate a couple of bad swings I think I can still put together a good golf round. I can still hit wonderful tee-shots, some wonderful iron shots, I can still hit a lot of greens. So I say to myself, 'you know what, even though I have these bad shots, in the main I can still play like everyone else does.' I know I can still play very decently."

As a past Open champion Duval has an exempt spot for the tournament until he is 60. He is cagey about how long he can go on for, but decided not to pass up the chance of these two weeks of links golf in Scotland.

"I don't get access to many tournaments now. I don't have the ability - or should I say the status - to get into certain events. So this summer, when I got the opportunity to go and play two weeks of golf in Gullane and then St Andrews, I didn't want to pass it up.

"I don't know what my future holds. I'd like to play more. If you are only playing five or six times a year, it gets pretty difficult. If I could play a 15-tournament schedule I feel I could be more competitive.

"Right now I'm just looking forward to playing St Andrews. I still feel that I can play pretty well. My game is there."

As I shook hands and bade farewell to the stoical Duval, it was hard not to think of the stellar career this golfer should have had. But, as he says himself, it wasn't to be.