The personal best Sesay recorded in the Adidas international meeting at Loughborough last month, 1min 46.05sec, elevated him to 28th place in the British all-time ranking list - 4.32 seconds short of the world record Sebastian Coe set in Florence 16 years ago. The acceleration which took him clear in the final 200 metres, however, had critics and coaches comparing the 24-year-old Leeds City athlete with the thoroughbred Coe and the only British man who has struck gold in an Olympic or World Championship 800m final since 1932, Steve Ovett.
It is just as well, perhaps, that Sesay happens to have a wise head upon his broad shoulders. "It doesn't bother me," he said. "The same kind of things were said when I was a promising teenager. It happens when any 800m runner breaks on to the scene."
It happened to David Sharpe after he shattered Ovett's British junior record and won the world junior title in 1986. Peter Coe predicted that the Geordie with the golden hair would assume his son's mantle as the world's leading 800m man. "Sharpe has to be the number one contender," Seb's father and coach asserted in 1987. Ten years on Sharpe, at 29, is a contender no more.
"It's fair to say I'll never run at international level again," he said. "I've had so many injury problems I'm semi-retired now. I might get back to running for my club but I'm discovering the things I've missed over the years - like walking in the Lake District on Sundays. Being described as 'the new Seb Coe' never bothered me and it shouldn't make any difference to Mark Sesay. He knows he's got a long way to go to be in contention for a medal at something like the World Championships. He'd have to be capable of running 1min 43sec to have a chance."
Sharpe is one of six British 800m men who have broken 1min 44sec and the last to win a major championship medal, albeit because he followed Tom McKean across the line, in second place, in the European Championship final seven years ago. Curtis Robb finished one place short of the medals at the 1993 World Championships in Stuttgart but, four years later, the Liverpool Harrier is still chasing the ghosts of the great British past.
Hailed as another Ovett after burning off the opposition in the UK Championships at Sheffield in 1992, Robb responded: "I won't consider myself in the same class until I've got time to do the Ovett wave in the home straight." At 25, Robb still has time on his side. A pelvic problem has halted his progress and, having failed to reach the finals at the 1995 World Championships and at the Olympics last year, he has devoted this summer to resolving it.
"Steering clear of injury is half of the battle," he said. Having just finished his medical finals at Sheffield University, fitting an international athletics career around working life as a junior doctor would appear to be another problematic half for Robb. "It's not going to be easy," he said. "but I think it can be done - if you don't have a social life, if you're a bit of a sad bastard."
By the time Robb returns to the track, Sesay will have had his chance to fly the British 800m flag, an opportunity that has been a long time coming. In 1989 he became the first British runner to break 1min 50sec as a 16-year-old. And at 18 he finished sixth in the European Junior Championship final. Robb took the gold medal ahead of him that day. Behind, in seventh place, was Vebjorn Rodal, the Norwegian who won the Olympic title in Atlanta last summer and who lines up as favourite in Munich this afternoon.
Sesay, a sports science student at Loughborough University, is making up for time lost to injury. He is doing so with guidance from Richard Hepworth, the Bradford teacher who also coaches Andrew Pearson, Britain's 5,000m representative in Munich. Hepworth's use of biorhythms in the plotting of his athletes' training schedules raised a few sceptical eyebrows - until Martin Steele won the Bislett Games 800m in Oslo four years ago in 1min 43.84sec.
With Rodal and the European indoor record-holder Nico Motchebon to contend with, today is unlikely to be Sesay's day. However, the powerfully built Yorkshireman happens to possess the kind of basic speed that blasted the golf-capped Dave ("the throttle") Wottle to surprise Olympic 800m gold on the same Munich track in 1972. The 46.22sec Sesay clocked for 400m last month is significantly quicker than the one-lap personal bests boasted by Coe (46.87) and Ovett (47.5). It is also faster than either Rodal (46.56) or Wilson Kipketer (46.85), the Kenyan-born Dane threatening to break Coe's 800m world record, have managed.
Sesay can recall running against Kipketer and Rodal in the junior 800m race at the Bislett Games in 1991. So can Curtis Robb. He was the winner. "It's all very well having potential," the potential two-lap world beater said. "You've got to do something with it. It's like Liverpool, the football club. It doesn't matter what you're capable of doing, you've got to do it. You've got to win something."
And, just like the trophy cabinet at Anfield, the major medals cupboard has been bare for Britain's 800m men for seven years now.