The FIFA World Cup in Brazil has taken centre stage recently but the United States' premier competition returns with Saturday's fixture at the Robert F. Kennedy Memorial Stadium in Washington pitting the Eastern Conference's leaders against the Western Conference's high-flyers.
Ben Olsen's DC United have tasted defeat just once in their past seven league games to sit atop the standings on 25 points after 15 games, two points clear of nearest rivals the New England Revolution.
In the West, the Sounders (32 points) are seven points clear at the summit after back-to-back wins, with Real Salt Lake (25 points) in second position.
Nigerian forward Obafemi Martins has played a big part in the Sounders' rise, scoring four goals in his past four games in MLS.
Seattle have enjoyed success against the capital franchise in recent memory, with the Sounders unbeaten in their four most recent meetings in all competitions, having won two (2-0, 3-0) and drawn two (2-2, 0-0).
The Sounders' hopes of maintaining that run of form against DC United has been boosted by the news that star forward Fabian Espindola will miss the next six weeks due to knee ligament damage.
Espindola has scored seven goals and assisted eight for DC United this season - no player has been involved in more goals thus far - and the pressure will be on Luis Silva to step up in his absence after he netted a hat-trick in the final game before the World Cup break.
In other fixtures over the weekend, out-of-sorts New England will be out to arrest a two-game losing streak when they entertain the eighth-placed Philadelphia Union on Saturday.
After five wins on the bounce, New England have suffered back-to-back defeats to the Montreal Impact (2-0) and New York Red Bulls (2-0).
New York and Toronto will go head-to-head in a mid-table clash in the East on Friday.
The Red Bulls were 3-1 winners against Real Salt Lake last time out, while Toronto edged the San Jose Earthquakes 1-0.
The Vancouver Whitecaps and Montreal Impact have a busy week ahead of themselves, with two games in the space of four days.
Vancouver and Montreal will do battle on Thursday, before the Whitecaps travel to the Colorado Rapids on Saturday, while the Impact are in action against the Houston Dynamo the following day.
The Portland Timbers face Sporting KC at Providence Park on Friday.
On Saturday, the Crew welcome Dallas to Columbus and the Los Angeles Galaxy travel to San Jose to play the Earthquakes.
Meanwhile, Real Salt Lake take on Western Conference cellar-dwellers Chivas USA.
