Fans, sponsors and TV executives sensed it, and now the WTA Tour has put it in black and white: Top women's tennis players pulled out of events at a record rate this season.

In an effort to address the issue, tour CEO Larry Scott called Friday for rules changes in 2007 that would double fines for withdrawals and reduce the number of events players must enter.

``The women's game has changed a lot over the last five to seven years in terms of the depth; the power with which players hit the ball; the rigors of the tour, mentally and physically,'' Scott said in a telephone interview from St. Petersburg, Fla.

``The game's changed a lot, but the structure and the demands on the players haven't changed. If anything, they've gotten tougher. That's what we're trying to fix.''

As if to illustrate Scott's point, U.S. Open champion Maria Sharapova withdrew Friday from the Moscow Open before her quarterfinal match, citing a right foot injury.

``I couldn't practice and even walk yesterday,'' she said. ``I have to pull out. I'm really disappointed, but I have no choice.''

At least spectators in Russia got to see her play one match. More than ever, leading women's tennis players are failing to show up at all.

Sharapova also withdrew from the Rogers Cup in Montreal this summer, an event that has hit hard by no-shows.

The list included France's Mary Pierce, Switzerland's Patty Schnyder, Russia's Vera Zvonareva, France's Amelie Mauresmo, Belgium's Justine Henin-Hardenne, American Venus Williams and Russia's Elena Bovina.

According to the tour, withdrawals from Tier I events _ the 10 most important WTA tournaments _ by players ranked in the top 10 more than doubled from 13 in 2005 to a record 31 in 2006.

Withdrawals at Tier I tournaments by top-10 players have increased 72 per cent over the past five seasons, the tour said, and for the first time, none of the 10 Tier I events featured more than five women ranked in the top 10.

And those statistics don't take into account the four Grand Slam tournaments or headline-grabbing players no longer in the top 10. Serena Williams missed Wimbledon and the French Open, for example. Venus Williams and defending champion Kim Clijsters withdrew from the U.S. Open.

``The last 12 to 15 months have created a sense of urgency for us,'' Scott said.

In recent weeks, Scott drew up proposals for next season he expects to be approved by the WTA board of directors no later than its meeting in Madrid in November:

_ reduce the number of WTA tournaments a player must enter from 13, probably to 12 (in addition to Grand Slam events and Fed Cup);

_ double fines for withdrawing, with the current maximum of US$20,000 rising to $40,000;

_ prevent players from getting wild cards into tournaments a week after withdrawing from another event.

Scott also wants to implement by 2009 some wider changes originally slated to go into effect in 2010:

_ shorten the season by two weeks so it ends in October instead of November, giving players an offseason that lasts two months instead of six weeks;

_ reduce the minimum number of WTA tournaments a player must enter to 11 or fewer;

_ add more breaks during the season, including changing Fed Cup dates so players aren't required to play right after Grand Slam tournaments.

Similar moves are being considered in men's tennis. ATP chairman Etienne de Villiers said in August he wants to figure out how to discourage top players from withdrawing from tournaments, and he raised the possibility of rankings point reductions. The ATP already is trying to reduce wear and tear by eliminating best-of-five-set finals at tournaments that use best-of-three matches earlier in the draw.

``I've gotten a lot of feedback,'' Scott said, ``from fans, television broadcast partners, our sponsors, plus the players themselves, saying, 'Help! We need to make some changes.'''