So it goes in the topsy-turvy morality play that is modern professional boxing. As one door swings obligingly open with the promise of a successful and lucrative future, another is slammed in the face of a man who is now staring harsh reality square in the face.

This has been a week when the career trajectories of Damaen Kelly and Wayne McCullough - two of the most talented and most courageous boxers this place has produced in recent memory - crossed momentarily before drifting even further apart.

The symmetry was strangely appropriate, because it was McCullough who first proved that there is a tenable professional future for talented amateur boxers provided they choose the right path and take the correct advice. In the fall-out from his silver medal at the Barcelona Olympics, McCullough ignored all the conventional routes and opted for the road less travelled, through the tough and uncompromising world of the American professional game.

It was an approach which reaped considerable rewards, including a world title and stand-offs with Naseem Hamed, for which McCullough's bravery and indomitable spirit received respect and admiration. But now it looks like his career has trundled down a siding from which there seems no practical escape route.

The problems started with an irregular brain scan in the run-up to what had been billed as his triumphant return to Belfast for one or two valedictory sign-off fights and rewarding pay-days. McCullough was denied a licence to fight by the British Boxing Board of Control (BBBC) in either Northern Ireland or Britain on foot of the findings of that scan, and months later that is essentially still the position.

In the intervening period, McCullough has made a trawl through some of the most eminent neurosurgeons both here and in the US and makes much of the fact that they all deem him fit to box and suitable for a licence. But that first scan, taken as a matter of routine before the original Belfast fight, continues to be the monkey that McCullough can't quite shift from his back. The BBBC has drawn its line in the sand.

The stakes were upped last week when McCullough made a fresh application for a licence to the BBBC, armed with the various second opinions that he has been given. Again that application appears to have been processed through another panel of medical experts, and the final decision to refuse it was grounded on the opinions of two further neurosurgeons.

A number of avenues, including a personal application, still remain technically open, but the room for manoeuvre seems increasingly limited.

With the considerable benefit of hindsight, this was perhaps not the best time to open up another front in McCullough's running battle with the BBBC. The calamitous injuries suffered by Paul Ingle in his IBF world featherweight title contest with Mbuelo Botile last year prompted a root and branch examination of pre-fight procedures, and a report detailing the subsequent findings was published in the early part of last week.

The recommendations centred mainly on the thorny issue of weight loss and the effect dehydration can have in the lower weight divisions. And although the regulations with regard to the monitoring of potential brain problems have been in place for some time, the overall issue of safety in boxing was placed firmly in the spotlight. With so much television revenue on the line and an acute awareness of what the loss of that could mean, the pressure was very much on boxing to show a clean pair of hands to a questioning media.

The mixed signals sent out had the BBBC been, on one hand, copper fastening safety procedures and, on the other, backing down from a very public position it had taken in relation to an irregular brain scan would have provided a feeding frenzy for those who are lining up against professional boxing. The risk of a public relations disaster for the BBBC was simply too huge to countenance.

ALL OF this wrangling and tales of medical experts, rather than the boxers themselves, trading blows must seem a world away to Damaen Kelly. At the moment Kelly finds himself at the polar end of the boxing spectrum to that occupied by the unfortunate McCullough. On Saturday night in London he made a comfortable defence of his IBO world flyweight title against the Mexican Paulino Villalobos, and already sights are being set on a unified world title fight later this year.

While Kelly opted to stay in Belfast when he moved to paid boxing, he didn't cut his ties with the amateur set-up that had nurtured him and helped him to progress through the ranks. He may be managed by Frank Maloney, but the nuts and bolts of his preparations and training are looked after by long-time coach Michael Hawkins. This has proved invaluable to Kelly, who remains as grounded and as unassuming now as the shy amateur of a few years ago.

So far Kelly's professional career has been measured and sure-footed, and as he continues to consolidate his position among the world's best in his division there are new targets. A contest against the WBU champion, Peter Culshaw, has already been mooted with Kelly's technically gifted style expected to prevail. But even here there are one or two darker clouds threatening to come into view.

There can be no questioning of Kelly's technique or his courage, but one or two niggling doubts remain about his punching power and his propensity to cut up badly. One of these problems on its own would be manageable, but the presence of both does have a constraining effect. The future will tell its tale, but the likelihood is that anything Kelly achieves from here on in is likely to be hard fought and hard won.

Wayne McCullough, another boxer hamstrung by the lack of a really telling punch, knows all there is to know about that particular journey. He is nearing the end while Kelly has not really hit his stride yet. But both can testify that, whatever admirable qualities a boxer might have, it is human frailty that gets you in the end.