Craig Mitchelldyer/Portland Timbers

Six days ago in Texas, the Portland Timbers battled through the loss of three starters to injury to see out a 0-0 draw in the first leg of their Western Conference Semifinal matchup against the Houston Dynamo.

Now, the stage for Sunday evening's second leg in Portland is set. The Timbers move on with a win. Houston advances with a win or a scoring draw. A second straight scoreless draw would send the game to extra time and, if needed, penalties. For both teams, the season — and a date with Seattle — is on the line. (4:30 p.m., TV on Fox Sports 1).

The History

All in all, Monday's first leg was a rather drab affair. Houston struggled to create offense from the run of play, while the Timbers were decimated by injuries. Both teams suffered for the state of the field at BBVA Compass Stadium, which was borderline unplayable.

We can't know for sure whether the field conditions had any part in the multitude of injuries that the Timbers suffered, but we do know that the club's record without Diego Chara — 0-8-4 in their last twelve games with a -14 goal different — is abysmal.

The good news for Portland is that the Dynamo have had a similarly abysmal record in Portland in recent times. In their five trips to Providence Park in the last six years, Houston has departed with just a single point.

The last of those trips came in the second week of this season, all the way back in March, Portland won an up-and-down thriller 4-2.

The Tactics

For the Timbers, it's all about who will be able to play.

Here's what we know for sure: Diego Chara, who broke his foot and had surgery on Friday, is out. So is Fanendo Adi, who saw a specialist in LA for the hamstring problem that has now kept him sidelined for nearly three months.

The Timbers have four other injury concerns: Larrys Mabiala, Sebastian Blanco, Darlington Nagbe and David Guzman. Of the four, two of whom didn't travel to Houston and two of whom left Monday's game injured, Mabiala's injury is feared to be the most serious. If he's out, as seems likely, Roy Miller will replace him.

Craig Mitchelldyer/Portland Timbers

The Timbers were more confident in the status of the other three players. Guzman picked up a knee sprain during the team's Decision Day win against Vancouver, but he has been named in the Costa Rica squad for next week.

With Chara out, and Guzman questionable, Nagbe is almost certainly going to play in central midfield if he's fit. The U.S. international's withdrawal from the game on Monday was described as "precautionary." If Guzman can't go, Lawrence Olum and Amobi Okugo are midfield options.

Then there's the case of Sebastian Blanco, who burned off a layer of skin on his foot with boiling water last week and remains questionable. Dairon Asprilla will either start in Blanco's wing place or Nagbe's; if Blanco can't go, Porter has a number of options, none of them good.

The Dynamo, this week, lost a key starter of their own when goalkeeper and MLS Player of the Month for September Tyler Deric was arrested early Tuesday morning and charged with misdemeanor assault in connection to an alleged domestic violence incident.

Deric has been suspended indefinitely by the league, which means that backup goalkeeper Joe Willis will make his first start since July 1 on Sunday night.

But while that's a big question mark for the Dynamo, Houston manager Wilmer Cabrera's biggest task is getting his offense going. We could see Ricardo Clark and Alex return to the lineup in midfield, while Cubo Torres — who has scored in his two of his prior three starts at Providence Park — could come in up top.

Houston almost certainly has to get at least a goal. No team has shut out Portland at home all season, and the Dynamo's defense will be without its starting goalkeeper, left back, and right center back on Sunday night.

The Timbers' posture in the game will depend somewhat on the personnel they have available, but the expectation is that they will come out attacking. That will suit the Dynamo fine, as they'll likely look to absorb pressure and counter.

In the spring game, that gameplan worked for a half before the Timbers' attack overwhelmed Houston and turned a 2-1 halftime deficit into a head-turning win. One thing is for certain: this game, with the aid of a top-quality surface and atmosphere, will be played better and faster than the first leg was.

The Lineups

Portland Timbers

1 - Attinella
5 - Vytas
24 - Ridgewell (C)
7 - Miller
2 - Powell
20 - Guzman
6 - Nagbe
10 - Blanco
8 - Valeri
27 - Asprilla
11 - Mattocks

Houston Dynamo

31 - Willis
2 - Anibaba
3 - Machado
4 - Senderos
7 - Beasley
5 - Cabezas
13 - Clark (C)
14 - Alex
17 - Elis
12 - Quioto
9 - Torres

The Pick

So much is up in the air with the Timbers' lineup, as well as Houston's, this is an extremely difficult game to call. If the Timbers have the likes of Nagbe and Blanco available, they should win. If they don't, it's a tossup. Either way, though, it's hard to see this team's season ending at home. Portland gets through 2-1.