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.
"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.
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.
"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 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.
