NO. 4 LOS ANGELES GALAXY AT NO. 3 SEATTLE SOUNDERS FC6 p.m., CenturyLink Field.TV: ESPN. RADIO: 97.3 FM.REGULAR SEASON LEADERS: For L.A.: G 16, Robbie Keane; A 14, Landon Donovan; S 94, Keane; SOG 43, Keane; GAA, 1.33, Josh Saunders. For Seattle: G 14, Eddie Johnson; A 13, Mauro Rosales; S 126, Fredy Montero; SOG 46, Montero; GAA 0.73, Michael Gspurning. HEAD TO HEAD: Los Angeles leads 7-3-2, including playoff results. The Sounders swept at home this season: 2-0 on May 2 and 4-0 on Aug. 5. The Galaxy won the only previous playoff series, in the 2010 first round, and leads this series on the basis of a 3-0 win last week in Carson, Calif.NOTES: This is the deciding match of an aggregate-score series for the MLS Western Conference championship. If the aggregate score is tied after 90 minutes, there will be 30 minutes of extra time. If the tie remains, the series will be determined by penalty kicks. … Seattle has scored three or more goals five times this MLS season. … L.A. has advanced four out of five times when going into the second leg of a series with the lead. … The Galaxy leads the league in most playoff games won (37) and playoff goals scored (102). The club is defending MLS Cup champion, and has made the final two of the last four seasons. Coach Bruce Arena leads MLS with 25 career playoff victories. … Keane has four goals in these playoffs (two in each of the last two games) and is tied with Houston’s Will Bruin for the postseason lead. Teammate Mike Magee has three goals. Donovan and defender Sean Franklin are tied for the postseason lead with three assists. Donovan is the MLS career playoff leader with 21 goals. … The referee is Mark Geiger. … The band Presidents of the United States of America will perform at halftime. … More than 43,000 tickets have been sold, meaning this will be the largest crowd ever to watch an MLS playoff game other than MLS Cup. Tickets remain available.QUOTABLE: “It’s a chance to create a very historic moment for our club and for league history, because we’ve built that kind of a hole. Either we do it or we don’t do it; but we feel confident that we can create chances and we can score goals. We’ve just got to finish the chances that we create and not give anything up.” – Sounders coach Sigi SchmidNEXT: The series winner advances to MLS Cup on Dec. 1 against the winner of the D.C. United-Houston Dynamo series, which also resolves today. The loser’s season ends.