Late Saturday night at MCI Center, Chinese skating pair Xue Shen and Hongbo Zhao attempted a quadruple throw salchow. Zhao overthrew and Shen crashed to the ice, landing on her knee and twisting her right ankle, her coach said yesterday.

Whether the reigning world champions will compete in the World Figure Skating Championships pairs short program at 7 tonight is questionable.

After skipping practice yesterday afternoon, Shen attempted to skate in the evening at Washington Convention Center, but she left the ice hopping on one leg after one lap. She resumed practice but did not attempt any jumps or throws and spent the majority of the time on the sidelines talking with Coach Bin Yao.

"Today it was better," Yao said. "She wants to [compete], but [it's going to] depend on practice" today.

With stiff competition expected from Russians Tatiana Totmianina and Maxim Marinin, even a minimal setback could be costly.

Instead of her scheduled afternoon practice yesterday, Shen saw a team physician and was treated with ice and acupuncture for her swollen ankle.

Shen and Zhao, the first from their county to win a world championship, won three Grand Prix events this year but were defeated at the ISU Grand Prix Final in St. Petersburg by Totmianina and Marinin. The Russians won all six events they have entered this season, including this year's European championships and, most recently, the national championships in Dallas.

While aware of Shen's injury, the Russians said it wouldn't change their routine, which now includes an extra lift.

"This is the final competition, the end of the season, and we're expecting to show our best result," said Marinin, who earned a silver medal with Totmianina a year ago. "We're skating for ourselves."

U.S. Pairs Show Nerves

Two of the three American pairs are making their first appearance at the world championships and had a rocky practice. Rena Inoue fell on the release of a throw from John Baldwin and slid into the boards, and Kathryn Orscher landed in a split -- and tears. The experienced pair -- Tiffany Scott and Philip Dulebohn -- had no problems.

"It's always difficult your first year," said Dulebohn, a native of Silver Spring who placed seventh in last year's world championships with Scott. "We were very fortunate our first year to skate well and place in the top 10 . . . . that's very difficult to do."

Scott and Dulebohn placed first at the national championships and have been "fiddling around" with a second side-by side triple in the middle of the program. They said they will probably keep the double axle instead.

"Our goal is to do two clean performances here," he said. "That's what we want to end our season with. . . . We're just hoping to be in the top seven."

Weiss Right at Home

Michael Weiss, reigning national champion and a resident of McLean, made his official practice debut in front of an adoring crowd and family members waving American flags.

He signed several autographs after a smooth performance, and Coach Don Laws said Weiss, who has added a triple axle to his routine, is ready for this morning's qualifying round.

"He's in great shape, physically, mentally, psychologically . . . He's in his home town, what more could you ask for?" Laws said. "He knows his adrenaline will be rushing so he'll do his utmost to contain that and make the best use of it."

Weiss, who regularly practices in Laurel, chose to stick with his normal schedule and had not joined his American colleagues for the first two practice days.

"It was a clean practice, not perfection, but we want that for the programs," Laws said.

"We've been working on a steady basis and we have a system. They do the tour at so many ice rinks they know them all. He wanted to keep his training schedule going and just come in here and experience the ice with his program and music at least one time."

Replacement Referee

Assistant referee Gale H. Tanger has been named the replacement for Russian referee Alexander Lakernik, who had administrative visa problems and was unable to leave his country in time for the event. Fabio Bianchetti, a member of the ISU technical committee, will be an assistant referee. . . .

The men's qualifying free skate draw was announced, and Weiss will skate today just before noon. Japan's Takeshi Honda will skate around 12:30 p.m., Tim Goebel just after 3 and Russia's Evgeni Plushenko at 3:30. . . .

Sasha Cohen arrived yesterday and is scheduled to practice this morning from 8:40 to 9:15 at MCI Center and 2 to 2:35 p.m. at the Washington Convention Center.

Russians Maxim Marinin, Tatiana Totmianina will be favored if Chinese pair can't perform. Regardless, "we're skating for ourselves," Totmianina said.