Carlos Ruiz's bicycle kick early in the second half at RFK Stadium last Saturday was the highlight of the week in MLS and will probably end up being voted the goal of the year. What D.C. United will most remember about the Dallas forward's spectacular shot, however, is the sequence leading to the goal -- a defensive breakdown that was ultimately responsible for another early-season loss and raised serious questions heading into tonight's match at San Jose.

It began, innocently enough, with a throw-in by Dallas's Bobby Rhine on the right sideline. Roberto Mina took control at the top corner of the penalty area, but none of the three approaching D.C. players was able to shut him down. Mina chipped the ball past three other opponents to Ruiz, who had at least five yards of space with which to work.

If not for his flashy nature, Ruiz could've settled the ball and taken a touch before shooting. The fact that he had that option was what disturbed United's players and coaches the most.

"It never comes down to one play," defender Brandon Prideaux said. "It's always a series of things. We needed to get closer to the guy who crossed the ball, and I should've been there. If we had done what we were supposed to do before the cross, the goal never happens."

Although United (3-4-2) is fifth among 12 teams in goal allowed, defensive failures have cost the club several times. With the offense failing to find a consistent rhythm from week to week, there isn't much room for error at the other end.

Commenting on the build-up to Ruiz's goal, Coach Peter Nowak said: "We can stop the play much faster. We cannot stop the play when the ball is already in our box. The ball is supposed to be stopped someplace else. This is the main point."

United's defense has been in flux all season. Prideaux and Bryan Namoff missed several games with injuries, David Stokes has been in and out of the lineup because of his inconsistency and, just last week, veteran Mike Petke was traded to Colorado to make space for an unspecified Argentine defender whom the club hopes to acquire this summer. United also recently signed John Wilson, an outside back with some MLS experience.

The blame can't solely rest on the defenders, however. United's midfield hasn't pressured the ball as effectively as it did during last season's championship run, allowing opponents more time and space to create opportunities.

"We're better than we were at the beginning of the season," Prideaux said. "We're still not quite as sharp as we need to be. We still, at times, make mistakes. Players are good enough in this league that, if we do make mistakes, we're going to get punished."

Tonight, United will face a San Jose squad missing two of its most influential attacking players: forward Brian Ching and midfielder Brian Mullan. They are sidelined for several weeks with hamstring and ankle ailments, respectively. The Earthquakes have also lost defenders Troy Dayak and Craig Waibel to season-ending knee injuries.

Midfielder Josh Gros will return to United's lineup after serving a one-game suspension, but midfielder Clyde Simms is on U.S. World Cup qualifying duty and teenager Freddy Adu has rejoined the U.S. under-20 national team for several weeks.

Nowak complained last week that his team moved the ball too slowly on the attack, something that can't be repeated tonight if United has any hope of winning because Spartan Stadium's narrow dimensions leave little time to make decisions. United hasn't won in San Jose in seven years and is 2-6-3 overall there.

United Notes: Andrew Weber (New Mexico) signed a developmental contract and will be the club's third-string goalkeeper.

FC Dallas's Bobby Rhine, left, Carlos Ruiz and Ronnie O'Brien celebrate Ruiz's goal off a bicycle kick against United last week. "If we had done what we were supposed to do . . . the goal never happens," said defender Brandon Prideaux.