THE World Tour Finals, held at the end of the tennis season every year, should be a tournament of the highest calibre. It is the sport's most prestigious competition outside the four majors, and is supposed to feature its top eight male players. Yet this year's event, which starts in London on November 20th, will probably fall short of expectations. Four of the qualifiers have either pulled out of recent tournaments or struggled through them because of injuries. A troublesome shoulder forced Serbia's Novak Djokovic, currently the world's top-ranked player, to quit last week's Paris Masters before the quarterfinals. Having strained a hamstring at the same venue, Mardy Fish, the only American in the top eight, is now a major doubt for London.

The rigours of today's schedule are chiefly to blame for the sorry condition of the sport's elite. Besides the grand slams, players must compete in all nine so-called “Masters 1000” tournaments, except Monte Carlo (which lost its mandatory status in 2009), and at least four “500” competitions each year. Winners get little time to recover between events. And the endless cycle of the Davis Cup, which pits nations against one another, is an additional burden. Twice in the last two and a half years, stress-related injuries have stopped grand-slam champions from defending their titles. It would be a disaster for the game if damage caused by scheduling demands ended the career of a great player in his prime.

A few top-flight players, including Spain's Rafael Nadal and Britain's Andy Murray, have been agitating for more time off. Yet the Association of Tennis Professionals (ATP), an amalgam of players and administrators that runs the circuit, is in a quandary. Downgrading the status of any tournament would provoke a backlash from its backers. Indeed, when the ATP made the German Tennis Championships optional in 2007, it was sued (unsuccessfully) by the German and Qatar Tennis Federations, the tournament's co-owners.

Nor would most professionals support such a change. Because winners and finalists take by far the biggest share of prize money, most players must maximise their tournament participation to generate a decent income and fund a lifestyle of expensive coaching and international travel. They also tend to exit competitions in their early stages, meaning they suffer less fatigue than their more successful rivals, and are not as prone to injuries.

Not everyone has sympathy for Mr Nadal and Mr Murray. Professional sportsmen who grumble about their circumstances are typically portrayed as pampered and spoilt celebrities. After adding his own voice to complaints about the schedule, Andy Roddick, a former grand-slam winner, was quick to point out that tennis awards a relatively small percentage of its revenues to players when compared with sports like basketball. ATP authorities, for their part, have already made numerous concessions: increasing prize money; replacing some best-of-five-sets matches with best-of-threes; and arranging for the World Tour Finals to come straight after the Paris Masters in 2012, giving players a longer break at the end of the year. Moreover, some players make decisions that seem to undermine their demands. Although Mr Nadal has recently been heading up calls for a less-taxing schedule, he objected to the downgrading of Monte Carlo. He also regularly exceeds the minimum participation requirement, as do other top-ten players.

Two possible solutions spring to mind, although both would encounter resistance. First, authorities could try distributing tournaments more evenly throughout the calendar year. Three of the four majors, and a number of second-tier competitions, are crammed into a four-month period between late May and early September. Yet from then until mid-January, when the Australian Open starts, there are few tournaments of real significance apart from the World Tour Finals. Spacing out the slams, in particular, would ease the pressure on players' bodies and reduce the risk of injuries.

An even more controversial move would be ditching the Davis Cup. Far from being the tennis equivalent of football's World Cup, it attracts relatively little interest outside hardcore tennis circles. It is confusingly structured, with countries competing for promotion to a higher group even as the semi-finals are underway, and anticlimactic, extending across nine months of the calendar year before starting again after a three-month hiatus. Much better would be a proper tennis world cup once every two or four years, played over three or four weeks in one place.

The World Tour Finals will be the first time all the top players have been in the same location since the US Open, when the full extent of their concerns became apparent. In the following weeks, there was even talk of a strike, which would be the first since 1973. Fear of adverse publicity may have prompted Mr Murray to strike a more conciliatory tone in the last few weeks. But authorities would be foolish to think that means they can do nothing. More than most sports, tennis depends on its biggest stars for its appeal. Lose any and the consequences could be dire.