GOODWILL GAMES : The World Changes Quickly for Trenary : Figure skating: World champion could retire, turn pro or move to Italy with her coaches. For now, she’ll just pretend Yamaguchi is No. 1.

The first time Jill Trenary competed in the Tacoma Dome, the figure skating Establishment considered her as one of several young performers who could emerge as the second-best skater in the United States.

The skating Establishment did not know Trenary. During those 1987 U.S. Championships here, she told reporters that she would not concede first place to anyone, not even reigning world champion Debi Thomas, then backed up her words by winning the national title.

Three and a half years later, Trenary, who celebrated her 22nd birthday Wednesday, is a three-time national champion and the reigning world champion. She has nothing to prove at the Goodwill Games, where the female skating competition began Thursday night with the original program.

Yet, she still has motivation, even if she has to invent it. She said she is pretending that her No. 1 rival in the United States, Kristi Yamaguchi of Fremont, Calif., is the world champion.

“It’s just kind of a joke, but you can’t take this competition seriously,” Trenary said, explaining that she only recently began training after completing a North American tour that followed her victory in March at the World Championships.

“I’m not at my very best. But, obviously, I want to skate well. I don’t want to make a fool out of myself. I want to win. That’s the competitor in me coming out.”

The competitor, however, may not have a place to compete after the Goodwill Games.

When Trenary won the world championship, she got her edge over the defending champion, Japan’s Midori Ito, in the compulsory figures. But the figures have been eliminated from international competition, causing Trenary to wonder whether she should retire.

“The sport is changing, not to my advantage,” she said. “I’m not saying that I can’t do well, but we all know that the figures helped me out.”

On top of that, her coaches, Carlo and Christa Fassi, are moving this summer to a rink in Milan, Italy. Trenary is from Minnetonka, Minn., but has been training with the Fassis at the Broadmoor World Arena in Colorado Springs, Colo., since she was 15.

Asked to discuss her options, she said, “Everything’s an option.”

She could begin seriously considering offers she has received from ice shows and turn professional. She may even be able to maintain her competitive edge if plans to organize a professional skating circuit materialize. Two-time Olympic champion Katarina Witt of East Germany said this week that she is interested.

“It would be fun to compete against Katarina and Debi again,” Trenary said.

But that would leave her goal of winning an Olympic medal unrealized. She finished fourth in 1988 at Calgary.

“Part of me says it’s time to go out,” she said. “But another part of me says I’m crazy to give up a chance for that medal.”

If she decides to continue competing through the 1992 Winter Games in Albertville, France, she then has to make a decision about her coaching.

Her father, the most influential person in her career, has been trying to persuade her to move to Italy with the Fassis.

“I think it would be an experience, and it wouldn’t be for that long a time,” she said. “I could learn Italian and make new friends. But I don’t know if you want to experience all those things in the year before the Olympics.”

Even without much preparation, Trenary leads the eight-woman field into Saturday night’s freestyle program. Second and third after the original program were Nancy Kerrigan of Stoneham, Mass., and Yamaguchi. Surya Bonaly of France was fourth.

Experimenting with a new original program, Christopher Bowman of Van Nuys turned his required combination, a triple lutz-double toe, into a single-lutz-double toe and suffered for it.

Of eight skaters, he is in sixth place entering tonight’s freestyle program. The Soviet Union’s Viktor Petrenko is first, just ahead of two-time world champion Kurt Browning of Canada.

With 1988 Olympic and four-time world champions Ekaterina Gordeeva and Sergei Grinkov in the lead, the Soviets have a hold on the first three places after the pairs’ original program.

Natasha Kuchiki of Canoga Park and Todd Sand of Thousands Oaks are fourth. Sharon Carz of Playa del Rey and Doug Williams of Los Angeles are sixth.

The Soviets are first, second and fourth after the compulsory dance. Two-time world champions Marina Klimova and Sergei Ponomarenko lead.