'BAD BACKS' are used as a convenient excuse for everything from days without work to nights without passion. 'Och, it's my back, doc', is a lament heard everyday in surgeries throughout the world from slackers and genuine sufferers alike. The trouble is that, unlike most other ailments, it's well nigh impossible to tell the fakers from the genuine, achingly-sore article. Which brings us to Andre Agassi, his celebrated soreness of the spinal area and Hong Kong tennis fans' perception of the star's infirmity after his withdrawal from this week's Salem Open. Unlike recent cases of players pulling out of tournaments because of injury, there has been no manifestation of Agassi's apparent agony. Whereas television viewers saw Pete Sampras having an obviously-infected foot bandaged and Arantxa Sanchez Vicario limping on a severely-sprained ankle, press reports suggest that Agassi showed little sign of his affliction as the Pirate King went about his swashbuckling business. While paving the way for a possible pull-out with comments about his back, most of Agassi's remarks were decidedly upbeat regarding his play. 'The way that I was playing, I did not like his chances,' he trumpeted after a 6-4, 6-3 win over Scott Draper. 'I always felt like I was on the verge of breaking him and I was holding [my serve] pretty easy,' he declared after reaching the final with a 7-5, 6-3 victory over Wayne Ferreira. Agassi, of course, is no stranger to the procedures required to withdraw from a tournament. While he was the long-haired lobber from LA he disappointed a number of promoters, those in Hong Kong included, but now that he has been elevated to world number one you would think he would take on board the responsibility that goes with the position. He was committed to Hong Kong, a tournament which was seen several months back as a stepping stone to the top spot, and he should not have just cast it aside like some worn tennis shoe in order to concentrate on winning his second Grand Slam of the year, the French Open. It must have been galling for the sponsors, promoters and spectators to watch him play the Japan Open final knowing that he was giving Hong Kong a miss. Under ATP rules, he supposedly had to convince the tournament doctor in Tokyo that he had good grounds for withdrawing from the Salem Open but the reality is that the hoary old line, 'aagh, it's my back, doc' would have sufficed. It's unthinkable that the new top seed in Hong Kong, Michael Chang, would have let down his fans in a similar way. Just like a car that seems always to get you to your destination despite being patched up hundreds of times, Chang is ultra-reliable and the type of performer who plays on without nagging about nagging injuries. His appearance is one of the few good reasons why fans, who bought tickets assuming that Agassi would be present, should not be demanding their money back.