Four teams face the prospect of a knockout game for a place in the Conference semi-finals which start at the weekend. The other wild card game sees defending champions, Colorado Rapids, hosting the Colombus Crew on Thursday.
David Beckham and the L.A. Galaxy, who finished with the best regular season record to earn the "Supporters' Shield", begin their attempt to win their first MLS Cup since the English midfielder joined them five seasons ago on Sunday against the lowest-ranked wild card winners.
If the Red Bulls were to triumph in Dallas, then they would be the team to take on the Galaxy over two legs - pitting the two biggest name foreign players in MLS against each other.
The Red Bulls barely scraped into the postseason by finishing fifth in the Eastern Conference after coming up with three wins from their last five games. Henry finds the whole play-off system a little baffling.
"I will never get used to it; in Europe, Los Angeles would be champions," he said this week, comparing the MLS system, which mimics that of other North American sports, with the European model, which rewards the top finishing team in a league where every team plays each other twice.
"You fight all season like the Galaxy, but rules are rules. You have to adapt to it. I guess it can make things more exciting but I will never get used to it," he added.
PLAY-OFF SYSTEM
Whatever Henry's thoughts on the system, it means his team with a league record number of draws - 16 from 34 games - could have a chance to eliminate L.A who had 19 wins and just five defeats.
But getting to the Galaxy game is no easy matter. Dallas are tough opponents and the Red Bulls face them without their talisman - English forward Luke Rodgers.
Rodgers, who has scored nine goals this season, has a left knee injury and worryingly for Swedish coach Hans Backe, the Red Bulls have won only once this season without the aggressive striker.
"We have a frightening record without Luke," said Backe, who has yet to decide whether Jamaican winger Dane Richards or teenager Juan Agudelo will partner Henry in attack.
The game in Dallas will be decided on the night - with extra-time and a penalty shootout if needed.
The weekend's Conference semi-finals feature 2009 champions, Real Salt Lake, at home to the Seattle Sounders, while the Philadelphia Union host the Houston Dynamo in their first leg.
Along with L.A., the other team waiting to face a wild card winner is Sporting Kansas City.
