By Jose M. Romero

Major League Soccer’s Western Conference has produced the last three league champions – Real Salt Lake, the Colorado Rapids and the L.A. Galaxy – and also is home to the top club in the 2012 regular season, the San Jose Earthquakes.

Between the top-seeded Quakes and the No. 5 seed Vancouver Whitecaps, a team in only its second season of existence, the second through fourth seeds were separated by three standings points in the regular season. All of which should make the MLS postseason pretty entertaining in the West.

The Whitecaps and Galaxy open the postseason with Thursday’s knockout round match pitting No. 5 at No. 4. The Galaxy, the defending MLS Cup champion, probably feels a little disappointed with how its regular season went, and now must play the extra game just to keep its season alive.

Few give the Whitecaps a chance, though. They scored only 10 goals in 17 road matches this season and had a minus-14 goal differential on the road.

The Galaxy is a team with a strong Latino presence (including Brazilians) that will play a big part in the club’s postseason fortunes this year. Two of the best defenders in MLS are expected be in the starting lineup at some point in the playoffs, if not Thursday – American-born A.J. DeLaGarza and Omar Gonzalez.

DeLaGarza had played in every regular-season game until suffering a knee injury at the beginning of this month.

The winner of L.A.-Vancouver gets San Jose, which is led by defender-midfielder Ramiro Corrales, a veteran presence. Corrales has been slowed by a hamstring injury.

Pint-sized (5-5) midfielder Marvin Chavez of Honduras has playoff experience from his former team, FC Dallas, and his 13 assists led the Earthquakes this season. Fellow Honduran Victor Bernardez starts at defender with New York native Jason Hernandez, as does Mexican midfielder Rafael Baca.

The 2-3 series is a rematch of last season’s conference quarterfinals between the Seattle Sounders and Real Salt Lake. Seattle is at home for the first match of the two-leg series on Friday night.

The Sounders have been one of the league’s best regular-season teams in all four seasons of existence. But come playoff time, they have not been able to display such good form, or manage to get too far behind in the first leg of a series so as to make a complete comeback almost hopeless.

Injuries also have hurt the Sounders at this time of the year. In 2011, playmaking midfielder Mauro Rosales was unavailable. This season, leading scorer Eddie Johnson is dealing with a hamstring injury that could limit him when the playoffs start.

Without Johnson at full speed, the burden of scoring falls on Colombian forward Fredy Montero, who scored 13 regular-season goals in 2012 and has a knack for the dramatic. Rosales, from Argentina, will look to find Montero in space.

Defensive midfielder Osvaldo Alonso (Cuba) and defender Jhon Kennedy Hurtado (Colombia) will look to keep Real Salt Lake off the scoreboard.

Forward Sammy Ochoa (Mexico) and forward-midfielders David Estrada (USA/Mexico) and Mario Martinez (Honduras) are reserves, any of whom could be brought in during a match.

Real Salt Lake is a very good offensive team in the second half of matches and is one of the most Latino-centric teams in MLS. The forward combination of Alvaro Saborio (Costa Rica) and Fabian Espindola (Argentina) combined for 26 goals in MLS play this season.

Argentina’s Javier Morales guides the attack for RSL in the midfield, and defenders Tony Beltran (USA) and Jamison Olave play major minutes on defense.

American goalkeeper Nick Rimando has been chosen for the U.S. national team on several occasions and is one the best in MLS.