Sam Ortega/Portland Timbers
Five years after they first met in the MLS Cup playoffs, the Portland Timbers and Seattle Sounders have been drawn together in the postseason again — with the first leg of a Western Conference Semifinal edition of American soccer's greatest rivalry set for Sunday afternoon at Providence Park (2:30 p.m., TV on ESPN).

The Opponent

It's the Seattle Sounders, and it's a Seattle Sounders team that is absolutely rolling.

The Sounders have lost just two games since the beginning of July, winning 15 times en route to the best second half of an MLS season ever. They won nine games in a row to close out the summer, and then five straight to close out the regular season.

Seattle has been terrific down the stretch in each of Brian Schmetzer's three seasons at the helm, but this in particular has been a tour de force. Raul Ruidiaz has provided the goals, Nicolas Lodeiro is playing his best soccer since his first half season in the league, and the veterans around them are dialed in.

Defensively, with a double pivot of Osvaldo Alonso and Gustav Svensson in front of a backline anchored by Chad Marshall, the Sounders have been tremendous. They had the best defense in the Western Conference, and certainly know how to win in the playoffs.

Team speed remains a slight concern, but it shouldn't surprise anyone to see this team in MLS Cup for a third straight year.

The Tactics

The Timbers beat Seattle twice early in the year, but it was the teams' final matchup of the regular season — at Providence Park in August — that is most instructive for what we're about to see on Sunday and then again on Thursday.

Seattle won that game 1-0 on a late own goal despite being outshot 14-2 in the first half and 22-6 overall, dropping their lines, leaning on their defensive stalwarts, avoiding mistakes, and hanging around before springing forward.

Their plan for this one should be similar. The Sounders play a standard 4-2-3-1 with Alonso and Svensson both sitting in front of the backline, and let Lodeiro get on the ball and create as much as possible. They'll also push their fullbacks, which gives Christian Roldan and Victor Rodriguez the ability to seek the game out in the inside channels.

They'll be difficult to breakdown, though the Timbers, just as they did in August, will certainly get plenty of chances to try them.

The impetus is on Portland to score and win before heading north to play the second leg on short rest, but they won't necessarily sell out going forward. They've demonstrated time and time again this year that they're best defending deep and attacking on the counter, things that they did to great success on Wednesday.

One big concern for Giovani Savarese is the absence of Larrys Mabiala, who was sent off in Frisco and is suspended. He would have been responsible for locking down Marshall on set pieces, a task that might now fall to either Bill Tuiloma or Liam Ridgewell — neither of whom is nearly the same kind of physical presence.

For Tuiloma in particular, this is a huge stage. Will he be ready?

The Lineup

Portland Timbers

1 - Attinella
4 - Villafaña
24 - Ridgewell
25 - Tuiloma
16 - Valentin
20 - Guzman
21 - Chara
11 - Polo
8 - Valeri (C)
10 - Blanco
17 - Ebobisse

— Tuiloma, not Julio Cascante, appears set to step in for Mabiala. The Costa Rican will be the first center back option off the bench.

— Both Liam Ridgewell and Diego Chara are one yellow card away from a suspension, which, certainly in the latter case, would likely spell the end of the Timbers' season.

— Samuel Armenteros didn't get off the bench in the first leg, with Savarese preferring Dairon Asprilla in relief of Ebobisse with the Timbers trying to protect their late lead. If the Timbers are chasing a goal on Sunday, will we see the Swede?

Seattle Sounders

24 - Frei
5 - Nouhou
14 - Marshall
20 - Kee-hee
18 - Leerdam
4 - Svensson
6 - Alonso (C)
7 - Roldan
10 - Lodeiro
8 - Rodriguez
9 - Ruidiaz

— Left back Brad Smith is getting healthy for the Sounders, but hasn't played since September. Nouhou is the likely starter there.

— Same goes on the wing, where, even with Harry Shipp back healthy, Victor Rodriguez appears set to keep his place.

The Memory

These two great rivals have only met once previously in the postseason, in a 2013 series that ended with an absolute beatdown at Providence Park.

The Pick

Seattle, much as they did in August, will be more than happy to sit back and absorb pressure. The Timbers will have chances, but it'll finish 1-1.