The Red Bulls and Dynamo head to Red Bull Arena tied at 2-2, but New York must survive the absence of its most important defender.
Up 2-0 after Tim Cahill and Eric Alexander goals, the visitors were on their way to another big win at BBVA Compass Stadium, after they had already defeated the Houston Dynamo there in September and October by a combined score of 7-1.
However, Houston's playoff resiliency, and a completely unnecessary and potentially series-changing red card from Jamison Olave shifted the momentum entirely.
Ricardo Clark scored in the 51st minute, which was followed by Olave being sent off for a tackle from behind in the 65th minute. Houston would eventually grab a late equalizer to send the series back to Red Bull Arena at a 2-2 aggregate score.
With Olave suspended for the second leg, Markus Holgersson will slide over from right back to partner Ibrahim Sekagya at center back, and will likely be replaced by Brandon Barklage or Kosuke Kimura. However, the Red Bulls will have to reverse some troubling stats: The team is 0-3-2 in games Olave has missed this year, and has allowed 0.94 goals per game with Olave in the lineup, and 1.8 goals per game without him.
Combined with Houston's recent playoff success, Olave's absence means Wednesday's final leg will be a big challenge for the Red Bulls, despite the team posting a perfect 3-0-0 record against the Dynamo in the regular season.
Houston will be looking for its first win at Red Bull Arena, as Dominic Kinnear's side is 0-4-1 all-time at the stadium, and has not scored a goal there since 2011.