THE future of the Rugby World Cup Sevens is in doubt after organisers predicted a million-dollar loss for this month's inaugural event in Scotland. Just over a week before the event kicks off at Murrayfield, organisers admitted that they will make a substantial loss, with costs soaring to almost US$2 million and ticket sales taking barely US$1 million. Hongkong, who inspired the world tournament, are hoping to stage a possible second event in 1997, and are favourites to win the vote should the International Rugby Board decide to continue the tournament. But with a significant loss predicted, Hongkong Rugby Football Union secretary Peter Else said organisers may be forced to question the validity of such a tournament. A full house of 37,000 is expected for final day on April 18, but there are likely to be gaps on the two previous days and tickets will be on sale up to the last minute. ''I don't know what targets the organisers have set themselves or what they consider to be a loss,'' said Else. ''But if they do expect a substantial loss, they would most likely think again over whether to hold another tournament.'' But he said Hongkong will not lose out if the IRB decide to scrap the World Cup. He added: ''The Hongkong Sevens are considered the world championships anyway. We already know of a number of countries who are not keen on the World Cup. ''And you can't argue with the quality of the semi-finals line-up in Hongkong last month.'' Champions Western Samoa, Fiji, New Zealand and Australia played in those semi-finals, representing what are widely acknowledged as the world's top four sevens nations. HKRFU finance director David Bruce said there would be no danger of Hongkong making a loss should it host a world event in 1997. ''We have 18 years of experience in holding the Sevens and it is highly unlikely that we would make a loss.'' Last year's Hongkong Sevens were thought to have made a $5 million profit, and Bruce said the tournament has been making money for several years. In Scotland, referees will be told to crack down on tactical substitutions and off-the-ball incidents which have marred other sevens tournaments monitored by the organisers. ''The Scottish Rugby Union doctor on duty will have to sign the card for a substitution, which will take at least 30 seconds, a long time in sevens. It'll make teams think about replacing players,'' said tournament manager Charlie Bisset. ''The referees have been instructed to utilise the laws regarding injuries and not stop play unless they're serious. ''Off-the-ball incidents are not serious, but problematic. Jersey-pulling and obstruction can make a difference in sevens.'' The Hongkong tournament saw several instances of players being replaced during matches. It was especially so during the final when both Western Samoa and Fiji were forced to bring on replacements.