For the second time in six weeks, Major League Soccer's disciplinary committee is reviewing videotape from a D.C. United game in which an opposing player had his leg broken.

On Saturday night at RFK Stadium, Dallas midfielder Ronnie O'Brien suffered a broken right tibia late in regulation after colliding with United midfielder Dema Kovalenko. O'Brien, who is from Ireland, underwent surgery yesterday and likely will miss the rest of the season.

No foul was called and television replays seem to indicate that Kovalenko was trying to block O'Brien's crossing attempt with a slide toward the Burn player on the endline.

However, Dallas players and coaches were upset with Kovalenko and asked the league to review the matter. A decision could be announced today.

"I viewed it as a reckless play," Burn Coach Mike Jeffries told the Dallas Morning News. "I didn't think [Kovalenko] had a real chance of getting the ball, and he went in such a way where causing harm to an opposing player was a distinct possibility."

Asked about the incident yesterday after practice at the RFK auxiliary field, Kovalenko told The Post: "I'm not apologizing for anything because I didn't do anything wrong. I feel real bad for him, but that happens in a game. I can't believe anyone would think I would do it intentionally. I was just trying to block the cross."

Added United Coach Ray Hudson: "I think it's being cynical, biased and a little naive to think there was full intention on Dema's part to hurt the kid. It wasn't that way at all. . . . Dema did everything he could to stop the cross, and I still cannot figure [after watching the replay several times] how it led to the break, but it did. It's terribly unfortunate, but there was no malicious intent as far as I can see."

In late March, during a scrimmage at American University, United forward Hristo Stoitchkov broke two bones in the lower right leg of Eagles freshman Freddy Llerena on a midfield challenge.

Stoitchkov was given a red card at the time of the incident and later, after a review by MLS's disciplinary committee, was suspended for two league games and fined $2,000.

Surgery for Etcheverry

United captain Marco Etcheverry said he is planning to undergo surgery on May 19 because of torn meniscus in his left knee. The procedure will take place at the start of a two-week break between games, which means Etcheverry will probably sit out only one game, May 31 at Dallas.

Until then, he plans to play this weekend against the MetroStars at Giants Stadium and on May 17 against Kansas City at RFK.

Etcheverry was injured late in regulation of United's 1-1 tie at Colorado on April 26. He played with some discomfort against Dallas. . . .

Midfielder Bobby Convey and forward Earnie Stewart are in Houston with the U.S. national team for Thursday's friendly against Mexico, but they're scheduled to meet United in the New York area on Friday and be available for Saturday's game against the MetroStars.

For a change of pace, Hudson has tentative plans to hold practice Friday afternoon in Central Park. . . .

The club is awaiting international clearance before signing Jorge Geddes, an NCAA Division II first-team all-American at West Virginia Wesleyan, as its third goalkeeper. He is a native of Malawi in southeast Africa.

The Burn's Ronnie O'Brien, left, suffered a broken leg during 1-1 tie with visiting D.C. United on Saturday.