The US PGA tour may boast the best players in the world but when it comes to chivalry its fairways appeared populated by 24-handicap hackers yesterday as the already churlish welcome extended towards Annika Sorenstam by some of world's top male golfers took a distinctly ugly turn.

With Sorenstam out practising prior to teeing off today at the Colonial tournament here, it emerged that the tour might change its rules to ensure the Swede's historic first appearance in a men's professional event will also be her last.

The US PGA tour policy board, a hitherto obscure body but one with sweeping powers, will be asked to consider a ban on women playing alongside the men when it meets next month. Under the current rules, the US men's tour is open to both sexes. By contrast, the US Golf Association and the LPGA tour have a specific rule which bans any player from women's events "who was not female at birth" - a regulation thought to have been introduced to stop transsexuals playing in women's events.

"It's a major issue on our tour, no question. Players just don't think it's right. Our regulations were written at a time when people thought this would never happen - whereas the women's tour by-laws are specific," the American pro Tom Pernice, a member of the policy board, said yesterday.