D.C. United’s Dwayne De Rosario, right, tangled with Danny Cruz of the Philadelphia Union in an exhibition on Saturday. (Al Messerschmidt/GETTY IMAGES)

The five-member MLS disciplinary committee investigating allegations that Dwayne De Rosario head-butted an opponent in a preseason match last weekend is likely to suspend the D.C. United star, multiple people familiar with the situation said Wednesday.

If a penalty is imposed, De Rosario would miss United’s season opener Saturday night at Houston and possibly the home debut March 9 against Real Salt Lake.

The sources, who requested anonymity because they were not authorized to speak on the matter publicly, cautioned that the process is continuing and De Rosario, through the players’ union, would have the right to appeal a suspension. MLS Commissioner Don Garber hears disciplinary appeals.

Unlike some pro leagues, MLS does not announce such findings until the entire process is exhausted.

The committee interviewed several people who were involved in, or witnessed, the incident at the Disney Pro Soccer Classic on Saturday in Kissimmee, Fla., the sources said.

United Coach Ben Olsen and General Manager Dave Kasper declined to discuss the issue Wednesday. Asked Tuesday if he thought he would be suspended, De Rosario said, “I hope not.”

De Rosario was ejected in the 59th minute of a 2-0 victory over the Philadelphia Union after being involved in a midfield ruckus with Union captain Brian Carroll and former United midfielder Danny Cruz.

Cruz said De Rosario elbowed Carroll in the head and head-butted him on the nose. No other players received a red card. Cruz was not injured and remained in the game.

After the game, a United player, who didn’t want to be identified, said he apologized to Cruz for De Rosario’s behavior.

De Rosario has not addressed the allegations publicly, saying he hadn’t read Cruz’s postgame comments.

“It was a scuffle,” De Rosario said. “It was one of those unfortunate things.”

MLS officials did not want to comment and union chief Bob Foose was not available for an interview.

The match was not televised or streamed online, and one source said the disciplinary committee did not have any definitive video of the incident and had to rely on testimony from witnesses and game participants.

This case is unique for other reasons, as well. A red card assessed in the regular season results in an automatic one-game suspension and is subsequently reviewed by the disciplinary committee for further sanctions.

A preseason ejection does not carry over into the regular season, but MLS has the right to impose penalties for egregious acts committed by its players.

Union goalkeeper Zac MacMath received a red card early in the game, but because no violent behavior was alleged (he tripped Lionard Pajoy on a breakaway), he probably would escape further punishment.

During his 12-year MLS career, De Rosario has received just two red cards in 324 regular season and playoff appearances – both in 2006 while playing for the Houston Dynamo.

If De Rosario is suspended, United would have to continue to make do in competitive matches without its most influential attacker. A knee injury forced him to miss the last seven games of the 2012 regular season and all but the final 28 minutes of four playoff matches.

This preseason, Olsen has cited De Rosario’s superb fitness and form, and has pegged him to start at withdrawn forward. (He lined up in central midfield and forward last season.) If De Rosario is not available for early matches, Olsen might opt for an extra midfielder and rely on Pajoy as the lone forward – the same successful tactic employed in De Rosario’s absence last year.