Sunday afternoon at 1 o'clock at RFK Stadium, Washington's most successful professional sports team of the past four seasons will play one of its most crucial games.

No, not that football team. We have in mind D.C. United.

United's fans have lived this week with a sense of concern. Events seem to be combining against not only the team but also them, the most ardent fans. In the process of winning Major League Soccer's first two titles and finishing as runner-up last season, United has beaten Sunday's foe, the Columbus Crew, 11 straight times at RFK. Yet in this best-of-three Eastern Conference finals, it's almost imperative that United win yet again, in Game 1 at home. United appears vulnerable in a way it never has because of an improved Columbus team and because of United's personnel changes during the last offseason--a new coach and the loss of outstanding players.

United has struggled at times during the long, long season--a season that began before Major League Baseball's and continues. And now that a big game is here, kickoff time is inconvenient, if not impossible, for many of United's loyalists.

MLS's contract with Spanish-language television network Univision has locked United into a 1 o'clock kickoff at RFK, the same time that football American style will kick off at Redskins Stadium. Of far more regret to United officials and players is that 1 o'clock is a time when many of their fans are busy participating in the game themselves in youth and amateur leagues that can't reschedule on such short notice. The amount of soccer played on Sunday in the Washington area offers proof that life exists in forms other than couch potatoes and day-long expeditions to Landover when the Redskins play.

Kevin Payne, United's president and general manager, said that Univision, based in Miami and beamed to most metropolitan areas in the United States, was asked if it wouldn't mind a change in game time to 3 p.m. "But they said they had already promoted it for 1 o'clock," Payne said. A switch would have given soccer's participatory fandom in Washington time to get showered and onto the Metro to RFK, which, not incidentally, remains the easiest way to get to a football game in Washington.

It was quaint of MLS officials to think they might effect a network time change, even a network with a fraction the audience of the majors; it's still the network that says when to play, not the sport. MLS is still getting things straight in its fourth season, having this year ousted its commissioner and deputy commissioner and decided that the length of the 2000 season will be considerably shorter than this one. This regular season lasted seven months, followed now by playoffs that will drag on until Nov. 21. In covering all four seasons of the calendar, MLS has overlapped with every major U.S. sport.

MLS may end next season in the third week of October, but of more immediate concern locally is the state of the game out at United Park, in leafy Virginia.

"Columbus is a very dangerous team," United defender Jeff Agoos said the other day. "But we know if we play the way we want to play, we'll win. How many teams can say that?"

This year, United is taking instruction from Thomas Rongen, who has replaced Bruce Arena, now coaching the U.S. national team. In Rongen, United has a coach who shares some philosophies with his predecessor, among them putting forth an attacking, forceful, entertaining team. "He's a little more hands on than Bruce," Agoos said, "but not to the point of stifling your creativity."

Free-flowing, nonstop creativity, of course, is one of soccer's fundamentals, and it is an area in which United thrived under Arena. The game's continuity precludes effective surfing by TV viewers who might want to see parts of both the Redskins and United games. At the least, you need picture-in-picture for soccer if you hope to watch something else, too, because it's impossible to make any sense of soccer with a random click of the remote. A glance at soccer might create the impression that nothing is happening (the cynics' view of it), but staying tuned could reveal that any number of things are. A person is not likely to catch a goal in soccer by surfing and even less likely to click on to a nuance leading to a goal.

Yet as in other sports, it's difficult in soccer to sustain a winning streak such as United's over Columbus. "It gets tougher and tougher," Rongen said. "Now it becomes critical to maintain the mental edge. How do we not become overconfident?"

That's Rongen's job, as tough as any Arena faced during his three seasons.

Compounding fans' concern is the absence of Tony Sanneh, a midfield force on the right side who has moved on this season to Hertha Berlin in the German Bundesliga. Sanneh is tall and strong, and dangerous--a top prospect for the next U.S. World Cup team. John Harkes also is gone from the midfield, traded to New England because of salary-cap considerations; he helped establish United's work ethic. So, a coaching change, players departed and an improved opponent combine to level the field for this series.

Really, though, the only thing about Columbus that brings out envy in United is the Crew's new, 22,500-seat soccer-only stadium. Payne has a vision for something similar, maybe better, in Washington: "A European-style stadium, with a cantilevered roof, which also keeps the sound in and makes a better environment." In Payne's view, United's playing grounds would appeal as so many of the game's landmark sites abroad. Think about it.

CAPTION: In addition to Columbus at RFK Stadium, United is being forced to compete against the Redskins and local soccer leagues.