IN terms of quality, Glasgow's Great Scottish Run was rated the ninth best half marathon in the world in 1997. That's no mean achievement. But the event is now poised to soar considerably higher up the global rankings as the field assembled for this year's Irn-Bru XS sponsored event, which starts from George Square at 2pm tomorrow, oozes with top class talent.

South Africa's Olympic marathon champion Josiah Thugwane heads a quality cast which also includes Mexico's Pan American Games 5000m and 10,000m title-holder Armando Quintanilla, Kenya's Joseph Kibor, who is bidding for a hat trick of Glasgow wins after setting a course record time of 61min 46sec in 1997, England's Mark Flint who won in 1993, and other overseas stars Simon Lopuyet and Leonardo Guedes.

Quintanilla's compatriot, Dionicio Ceron, three times a winner of the London Marathon, had planned to take part but has withdrawn as he doesn't feel he is in good enough shape for the challenge. His absence, although disappointing, will not affect the overall calibre of the line-up.

Even at this late stage further star names may appear on the impressive guest list as Glasgow City Council's Ken Kelly, one of the event organisers explained: ''We put an invitation out to the South African Athletics Federation asking them to send some other members of their national team along with Thugwane. We haven't heard anything back, but you never know, some might show up.''

One of the fastest runners in the field is a man who was born in Glasgow but who, until now, has never competed in his native city. Paul Evans, a top British distance runner over the past decade, has lived in Lowestoft for most of his life and a deep Suffolk accent offers no hint whatsoever of his Scottish roots.

The 37-year-old, eleventh in the 1992 Olympic 10,000m and a past winner of the Chicago Marathon, is looking forward to the occasion, but admits he isn't sure what to expect.

He said: ''I've had a frustrating year but things are gradually beginning to fall into place again. This will be only my second race since dropping out of the London marathon in April, so I'm looking for a confidence boosting performance.''

Evans has a personal best half marathon time of 60min 09sec to his credit. It's one of the quickest times ever recorded but its authenticity has been called into question. He explained: ''I did it in Marrakesh a few years ago but many people don't recognise it as a legitimate performace because the guy who measured the course wasn't properly qualified and there are doubts over its accuracy. My next best time is 61-18 which I did at last year's Great North Run on Tyneside''. It's the sixth fastest ever by a Briton.

Paul wouldn't be drawn into making predictions about the likely outcome of tomorrow's contest. ''I've no idea about what sort of time I might do, I'm just hoping to be competitive after such a long absence from races of this quality. I beat Thugwane in South Africa at the beginning of the year so I'm not scared of him although he's a real quality performer. I'd say however that he's better over the full marathon and I'd reckon Kibor is a bigger threat over this distance. He's got the better of me before so I'm sure he'll be tough to beat.''

If he doesn't win, Evans hopes at least to do enough to gain selection to run for Britain in the world half marathon championships in Amsterdam at the end of September. The team will be selected later this month. He said: ''If everything goes to plan tomorrow and I turn in a reasonable performance I'd like to aim for the Chicago marathon in October. That being the case then Amsterdam would fit into my build-up and I'd be keen to be considered for the British squad.''

The women's start list is no less impressive than the men's. However, the disappointing news this morning for fans of Scotland's Commonwealth Games 10,000m champion Yvonne Murray is that the Motherwell athlete has been forced to withdraw from tomorrow's race with a bad leg injury. It is the latest in a growing list of setbacks for the 33-year-old who was hoping to compete in her first half marathon since dropping out of last year's Great North Run suffering from a bout of food poisoning.

Murray, who enjoyed a successful international track career which produced European indoor and outdoor championship wins, a world indoor title and a World Cup victory, has found the transition to the road-running scene anything but straightforward.

Her long-awaited marathon debut has been put on the back-burner on a few occasions. She originally planned to run London in April but postponed that in favour of an autumn race, possibly Chicago, claiming she needed more half-marathon experience before racing over the full distance. Now, depending on the severity of this latest injury, it seems that Murray will have to wait a bit longer before tackling the event in which she hopes to succeed at the Sydney 2000 Olympics.

Although Ireland's Catherina McKiernan, who clocked a course record of 69-00 in 1997 before going on to set the marathon world alight with superb wins in Berlin and London, is another absentee tomorrow, there is no shortage of other world class performers waiting to grab the limelight.

The Kenyans will be out in force, led by Luciano Subano, who won the Great North Run a few weeks after finishing runner-up to McKiernan in Glasgow last year. She's looking for the top prize on this occasion while her compatriot Joyce Chepchumba, fourth in the 1997 world half marathon championships but best known for dramatically outsprinting Liz McColgan to win the 1997 London marathon, will also come into the reckoning. Lornah Kiplagat, the 1997 Los Angeles marathon champion, completes a formidable African trio.

Then there's the considerable presence of Russia's Valentina Yegorava, Olympic marathon champion at Barcelona in 1992 and silver medallist four years later in Atlanta. She hasn't shown much form of late other than notching a couple of victories on the American road running circuit, but her pedigree is such that she cannot be discounted.

Westbury's Marian Sutton, winner of the Chicago marathon for the past two years and runner-up behind Subano in the Great North Run, is another who should not be ignored.

The leading athletes will be battling for a total prize package valued at #30,000 with the first man and woman to cross the finishing line in Glasgow Green each collecting #2500 plus a pair of air tickets to America. There's a further bonus of #750 for breaking the course record.

TV coverage: Scottish 2.0-3.30pm with commentary by Herald columnists Fraser Clyne and Sandy Sutherland

Route map - P14