Less than three weeks since suffering the first significant injury of his career, forward Freddy Adu has been cleared to play tonight when D.C. United faces FC Dallas in a U.S. Open Cup quarterfinal at Maryland SoccerPlex in Germantown.

"I feel great," he said yesterday. "I'm ready to play."

After spraining the medial collateral ligament in his right knee Aug. 6 in Chicago, Adu was ruled out for two to four weeks. But he resumed full workouts last week and looked sharp the past two days while not experiencing much discomfort.

With Jaime Moreno unavailable after playing for an MLS select squad in Madrid yesterday, Adu could step into the starting lineup. More likely, however, United Coach Peter Nowak will save him for the second half and call on him if the game dictates it.

"There's a little bit of soreness, but it doesn't affect my play," said Adu, who was playing as well as he had all season when he got injured.

"It's close to 100 percent. Peter probably won't play me for 90 [minutes], but I'll probably get some time. We'll see how it goes and then the goal is to be ready for Saturday" when United visits first-place New England in a regular season match.

United will also welcome back midfielder Ben Olsen, who missed last weekend's 3-2 loss to Los Angeles with a strained oblique muscle. However, Moreno and goalkeeper Nick Rimando won't return in time after facing Real Madrid.

United had planned to fly Moreno back early today in order to be available for the Open Cup game, but the MLS collective bargaining agreement prohibits players from playing twice in 36 hours (reserve matches are exempt).

If Adu doesn't start in Moreno's place, Jamil Walker probably will. Troy Perkins will start in goal for Rimando, the MLS leader in shutouts. Dallas midfielder Ronnie O'Brien also was in Madrid and will miss tonight's match.

The Open Cup, modeled after European domestic cup competitions, was formed in 1914 and involves professional, semipro and amateur clubs from around the country. Six quarterfinalists are from MLS and the other two -- the Rochester Raging Rhinos and Minnesota Thunder -- from the top minor league circuit. The tournament's top prize is $100,000.

With a victory, United would play the Rochester-Chicago Fire winner in a semifinal at RFK Stadium next month. Tonight's game was moved to the 3,200-seat SoccerPlex because the Washington Nationals are home this week.

Nowak hopes his team can improve on last weekend's subpar performance against the Galaxy, which snapped a four-game winning streak and a six-game unbeaten run.

"I will have to see how the team will respond," he said. "There are always these defining moments for the team and for the team character. This is the time to show what we're really all about."

United Notes: Forward Alecko Eskandarian, who has been sidelined since mid-June, is scheduled to see a concussion specialist in Pittsburgh next week. . . . Defender David Stokes is out at least two more weeks with ongoing ankle problems. . . . In tonight's other matchups, Los Angeles will visit San Jose and Minnesota will play at Kansas City.