Thursday at 8 p.m., PPL Park, Chester
Coaches: D.C. United, Ben Olsen (25-31-18); Union, John Hackworth (5-6-4)
Records: D.C. United, 13-10-5, 44 points; Union, 7-13-6, 27 points
United on the road: 3-9-1
Union at home: 5-6-2
Previous meetings: The Union won a 2-1 decision in extra time in the U.S. Open Cup on June 5. In two MLS games, United won, 1-0, at PPL Park on June 16 and the teams played to a 1-1 draw at RFK Stadium on Aug. 19.