NEW YORK, SEPT. 6 -- Arantxa Sanchez Vicario, Mary Joe Fernandez and Gabriela Sabatini seem to belong in a group, little separating them from Steffi Graf except that small gap between accomplished top 10 players and the steady winning dominance of a No. 1. In the women's U.S. Open semifinals Friday (CBS-TV, 11 a.m.), this clique of rising peers will compare their skills.

Everyone knows Graf can win an Open. What everyone wants to know about Sanchez Vicario, Fernandez and Sabatini is whether they can. So they circle around Graf, at 21 an increasingly harried and pressured champion after bouts with various health problems and off-the-court controversies.

Graf meets Sanchez Vicario, 18, of Spain, the squat clay-courter seeded No. 6 who upset her in the French Open last year but has taken just one set from her since. Fernandez, 19, of Miami, seeded eighth, reached the Australian Open final in January but has been injury-plagued since and seeks to demonstrate that she has the stamina to make an upward move against fifth-seeded Sabatini of Argentina in the other semifinal.

Sabatini, 20, has perhaps the most to gain, surpassed this season by younger players and struggling to reassert her position as a player once predicted as a coming champion and rival to Graf. Her only appearance in a major championship final came here in 1988 with a loss to Graf in her Grand Slam sweep.

Sabatini is perhaps most representative of the new breed, who have flashy early careers but are learning quickly it is easier to climb than it is to stay. In '88 she was breathing on Martina Navratilova for No. 2, but she has been inconsistent since, shoved from No. 3 in the world to No. 5 by 16-year-old Monica Seles of Yugoslavia.

"I think that what I need is to win a big tournament," she said.

The sensation of running in place is what caused Sabatini to make a major upheaval in her camp and training methods. She switched coaches, Angel Gimenez for Brazilian Carlos Kirmayr. She shed some of the muscle she gained to combat Graf, but which ultimately made her too slow. She has shown increasing confidence as a volleyer.

Sabatini knows full well that this Open in particular represents her best chance yet. Third-seeded Seles was eliminated in only the third round by Linda Ferrando of Italy, No. 2 Navratilova was stunned by Manuela Maleeva-Fragniere of Switzerland; each was her potential semifinal opponent. Fernandez should represent a relief, but instead the Miami teenager is a troubling specter. Their career record is 5-5.

Perhaps the only thing preventing Fernandez from garnering the kind of attention Seles and 14-year-old Jennifer Capriati have is her health. She has withdrawn from three of her last six tournaments with tendinitis in her shoulder, a pulled muscle in her back and torn cartilage in her right knee. She has crisp ground strokes and pace.

Sanchez Vicario, like Sabatini, has made large changes in her regimen in an attempt to press upward. She abandoned Juan Nunez, who coached her to her French title, in favor of Mike Estep, the former coach of Navratilova. She has become a fair net player, working tirelessly on her volleys, and has not lost a set in this tournament.

There has been a pattern to Graf's few losses: they have almost always been inflicted by ambitious players who are younger. Perhaps cracks in her veneer are to be expected after two virtually impregnable years and a record 160 weeks at No. 1.

But everyone is surprised at her joyless and vulnerable season that includes just one Grand Slam title, the Australian, after winning seven of the last eight. She has been plagued by a sinus condition that perhaps cost her the French title to Seles. Graf lost three straight tournaments, the German and French opens to Seles and a Wimbledon semifinal to Zina Garrison, before recovering something like her previous form. She showed some of the old ruthlessness in a fourth-round crushing defeat of Capriati, 6-1, 6-2, then her dispatching of Jana Novotna in the quarters, 6-3, 6-1. Graf is at her best when she is on a personal mission, and seems to be treating a third straight Open title as just that.