NEW YORK -- The top-ranked defending champions are among the walking wounded, a retiring legend is passing up her own going-away party and last year's top men's seed threatened to not show up at all. Is this any way to run a Grand Slam event?


The U.S. Open tennis championships begin on Monday with a lengthy list of question marks and both singles titles up for grabs.


"There is no overwhelming favorite. A lot of guys can win this year," said sixth-ranked American Michael Chang, who stamped himself a contender with a victory over two-time Open champion Stefan Edberg in the ATP Championship final earlier this month.


Top seeds Pete Sampras and Steffi Graf started the year in such dominating fashion that if early form had held, defense of their U.S. Open titles would have seemed a mere formality.


Sampras added the Australian Open and a second Wimbledon crown to his growing Grand Slam resume as he piled up eight titles and built the greatest lead over the world number two in the history of the rankings computer.


Graf played her first 27 matches of 1994 without dropping a set and won her first five tournaments, including the Australian Open.


But tendinitis in Sampras's left ankle has kept him sidelined since a Davis Cup tie in July and he has not played a tournament since Wimbledon, passing up the entire hardcourt season.


Graf is suffering from chronic back pain that forced her to seek treatment during the Canadian Open last week and to pull out of her final U.S. Open tune-up.


Sampras is determined to defend his Open title, but how effectively remains to be seen. "This is not the preparation I wanted for the Open but I'll have to make the most of it," he said after pulling out of his fifth successive event.


"Pete's lacking match practice and everybody is going to know it," says former Wimbledon champion Michael Stich, the fourth seed. "There are a lot of good players out there who have a good shot. That is going to make this year very interesting."


Graf's aching back comes on top of recent struggles with her confidence and her groundstrokes that began with a stunning first-round loss at Wimbledon.


The German star remains a favorite in the less competitive women's field. But she is sure to be tested by second-ranked French Open champion Arantxa Sanchez Vicario, who beat Graf at the Canadian Open, Wimbledon winner Conchita Martinez or Mary Pierce, who conquered the German at Roland Garros -- that is assuming Graf survives deep enough into the tournament to meet up with any of them.


The event that was supposed to be Martina Navratilova's Grand Slam farewell will go on without her -- for the first time in 21 years.


The four-time champion felt she was not up to the demands of the most gruelling fortnight in tennis and perhaps decided she would rather end with her inspiring run to this year's Wimbledon final, rather than risk a possibly embarrassing early ouster at Flushing Meadow.


"I'm just tired and out of shape," confessed the nine-time Wimbledon winner.


Joining the list of expected contenders who are far from the top of their game is second-ranked Croatian ace master Goran Ivanisevec, who is suffering from a hip injury.


And Jim Courier, last year's top seed who has plummeted from number one in the world to 11th, was so disgusted with his recent form after a second-round loss at Indianapolis that he threatened to walk away from tennis all together.


A change of heart brought the 1991 runner-up back to the U.S. National Tennis center practice courts this week. Courier called his recent tirade "a momentary lapse of sanity."


Edberg has three titles this year but no majors. He will try to change that here. "There's no clear-cut Open favorite. I give myself a chance."