Two weeks ago, in their first meeting since July, D.C. United and the New York/New Jersey MetroStars were involved in a pair of first-half scuffles and a halftime confrontation in the tunnel below Giants Stadium.

Imagine their temperaments by the end of this month after facing each other three consecutive weekends and four times over five weeks.

The next encounter will take place today at RFK Stadium in the regular season finale for both teams. Then it's on to the MLS playoffs, with United and the MetroStars colliding in a two-game, first-round series. Today's outcome between teams separated by one point in the Eastern Conference standings will determine their respective seeds and, consequently, who hosts the postseason opener next weekend.

"It's a baseball series, isn't it?" said Ryan Nelsen, United's New Zealand-born defender. "They're going to get sick of us and we're going to get sick of them."

United (10-10-9, 39 points) and the MetroStars (11-11-7, 40) provided MLS with its first genuine rivalry during the league's inaugural season in 1996, when the teams met in a fiercely contested playoff series. It continued for a couple of seasons before hitting a lull as one team or the other struggled.

This year, emotions are stirring again with each side believing it can advance to the MLS Cup in Carson, Calif., on Nov. 14.

"The closer you are [geographically], the more hated the opponent," United midfielder Ben Olsen said. "I don't think there's any love lost between us, but that's fine. That's what our league needs -- good rivalries. . . . There are a lot of territorial battles that happen [in sports], and this is ours."

Because of their proximity, the clubs decided a few years ago to compete for the Atlantic Cup, awarded to the team that wins the season series. The MetroStars won it last year, but United has a 2-1 advantage going into this year's finale.

The bigger prize, however, is to come out on top in the playoffs. Both teams are hungry for success, the MetroStars having underachieved for several seasons and United having gone five years without a postseason victory.

Today United would like to maintain its late-season momentum, which has resulted in four wins in the last five games to reach the .500 mark after a gloomy summer.

However, D.C. will be without the suspended Dema Kovalenko and Josh Gros, who have occupied the midfield flank positions for many weeks. Kovalenko received a red card and Gros surpassed the yellow card limit during last week's 1-0 victory over New England, a result that extended United's unbeaten streak at home to nine. Its last loss at RFK came five months ago to the Los Angeles Galaxy.

There really isn't any home-field advantage at stake for the two-game playoff series -- the higher seed hosts the second match, which would be followed by a 30-minute overtime period and penalty kicks, if the series is even -- but Coach Peter Nowak said his team's approach won't change today.

"It's still very important to go into it like we did a couple of weeks ago," he said. "Nothing is going to change from our standpoint, from our approach, to this game. There are still points to win. This is more important than anything."

United Notes: Defender Ezra Hendrickson has rejoined the team after playing three World Cup qualifiers for St. Vincent and the Grenadines. . . . The MetroStars are 2-5-2 in their last nine games, including a 1-0 loss to United on Oct. 2. . . . D.C.'s charitable arm, United for D.C., will hold a silent auction for game-worn players jerseys on the concourse near the main gate starting at 3:30 today.

"I don't think there's any love lost between us," said Ben Olsen, left, of D.C. United's rivalry with the MetroStars.