Santino Quaranta and Jamil Walker, two of D.C. United's most important attacking players, are questionable for tomorrow night's match against Universidad Catolica in Santiago, Chile, because of injuries suffered over the weekend.

Both players traveled with the team late yesterday, but their availability for the second and final leg of the Copa Sudamericana round-of-16 series will not be determined until tomorrow.

Quaranta, who can play forward or on the right side of midfield, suffered an injury to his lower leg during the second half of a 2-0 victory over the Colorado Rapids on Saturday at RFK Stadium. Walker, who scored against Catolica in the first leg last week in Washington, has a first degree ankle sprain.

Yesterday at practice, Quaranta participated is some drills before watching the rest, while Walker spent the entire session testing his ankle off to the side. The pair has combined for seven goals and nine assists in the MLS regular season.

"Santino looks pretty good," Coach Peter Nowak said. "The swelling went down and he just suffered a huge bruise. I think he's going to be all right. He'll wear bigger shinguards this time. I am concerned about Jamil so we have to see how he's going to feel."

If both are unavailable tomorrow, teenager Freddy Adu, who played only five minutes Saturday and 21 in the first Catolica match, would become a top candidate to start. If only Walker is out, Quaranta would probably start up front with Jaime Moreno and Adu would enter in the second half.

United and Catolica played to a 1-1 tie in the first meeting. The winner will advance to the quarterfinals of the 12-nation, 34-team tournament next month.

-- Steven Goff

Injuries could prevent Jamil Walker, above, and Santino Quaranta from playing tomorrow night.