Tied atop the group with four points, neither team is assured of advancing should this match end in a tie. If Morelia beats Club America (10 p.m. ET, TeleFutura, mlslive.tv), there would be a three-way logjam of teams with five points and tiebreakers would be needed to determine which two teams move on and which one does not.
Both MLS teams plan to be at RFK Stadium in November to play in MLS Cup, and neither has stood pat the past two months. Dynamo coach Dominic Kinnear has added players to strengthen his squad and D.C. coach Tom Soehn, after trading defender Facundo Erpen for veteran Greg Vanney, has recently installed Marc Burch at left back, with Josh Gros moving to the right corner.
Soehn will have Jaime Moreno available against Houston. He has yet to play in the SuperLiga because of a hamstring strain but has traveled with the team and could get some minutes, though Moreno's availability for a road match at New England Sunday is of greater importance, since Fred's red card against New York 10 days ago rules him out of that game.
Houston blanked Club America, 1-0, in its SuperLiga opener and should have beaten Morelia Sunday to clinch a spot in the semifinals, but conceded a comical equalizer and wound up tied, 1-1. Backup keeper Zach Wells' fumble enabled Marcio Batista to score the goal that prevented Houston from clinching a semifinal spot.
Forwards Joseph Ngwenya and Brian Ching, supported by Dwayne DeRosario and Stuart Holden, are forming a potent partnership up top and midfielder Richard Mulrooney has added experience to the midfield. In its last 14 games, Houston's only loss is a 1-0 setback to the Charleston Battery in the U.S. Open Cup.
Ching redirected a Mulrooney shot into the net for the goal that beat D.C., 1-0, when the teams played at Robertson July 8. United won the first meeting, 2-1, in late May; since then, Houston has added Ngwenya, Mulrooney and Nate Jaqua.
Club America and Morelia play at Dick's Sporting Goods Park after the MLS teams square off. If either Houston or D.C. wins, Morelia qualifies with a victory and shuts out the MLS loser. If the MLS teams tie, and Morelia wins, since none of the three teams has beaten the other, the first tiebreaker -- head-to-head results - decides nothing.
Next in the tiebreaker order are a) goal difference in all games; b) goals scored; c) drawing of lots.
The story so far, with goals scored-goals conceded in parentheses:
1. United 4 pts. (2-1); Houston 4 pts. (2-1); 3. Morelia 2 pts. (2-2); Club America 0 pts. (0-2).
Get out the calculators.