The onus on Sunday is on FC Dallas. Not only will the club be at home, but it needs a victory. Anything less will result in another early playoff elimination. The Seattle Sounders, conversely, are in the driver’s seat. A win or draw would see them through, and so would any one-goal loss but a 1-0 or 2-1 scoreline.

Scenarios for advancement might be different for the two clubs, but their missions heading into this weekend are exactly the same: win the game.

The second leg of the Western Conference semifinals between FC Dallas and the Sounders will take place at Toyota Stadium on Sunday night (7:30 p.m., Fox Sports 1), and both Western Conference heavyweights enter the showdown looking to land the knockout blow. The Sounders could, of course, opt for a more reserved approach after winning the opening match in this series, 2-1, last weekend, but head coach Sigi Schmid is going for the jugular.

That is not to say the Sounders will attack with reckless abandon. The club knows full well how alert it has to be defensively, especially after conceding an away goal to Fabian Castillo that could make things complicated.

“Anytime you have dangerous forwards, you’ve got to try and cut the service as much as possible,” Schmid told SBI. “A lot of his service comes from (Mauro) Diaz, so we’ve got to be aware of where Diaz is and we’ve just got to be aware of the game getting stretched. They’ve got players – (Michael) Barrios, Diaz, and Castillo – that are not real honest defensively, so if you lose the ball in bad parts of the field and unexpectedly, that’s when they become very, very dangerous.”

FC Dallas might thrive on hitting lightning-quick counterattacks through the likes of Castillo and Diaz, but it will probably be unable to get by on just that approach. The Texan club needs at least one goal, and the pressure is on it to take the game to a Sounders side that surely would not mind keeping possession and selectively choosing the right moments to attack.

FC Dallas is confident, however, that scoring opportunities will come throughout the course of the game. The Western Conference’s No. 1 seed scored an impressive 52 times in the regular season, and has plenty of attacking options capable of putting the ball into the back of the net.

In fact, FC Dallas felt a little unlucky to leave Seattle with a loss because of the amount of scoring opportunities that it had in the initial 90 minutes of the series at CenturyLink Field.

“I think we have to know how to make better decisions in the final third of the field,” FC Dallas head coach Oscar Pareja told SBI. “The Sounders come frequently and we know that and our players have that in their offensive skill set. We’re going to try to be more precise because we left a lot of chances in Seattle and could’ve come back with at least two goals from there.”

While much of the burden will be on the attack, FC Dallas’ defense also needs to hold its own. The back four did a solid job of limiting the two-headed monster that is Clint Dempsey and Obafemi Martins, but a couple of errors in the defensive third midway through the second half allowed the Sounders to find an equalizer last Sunday before Dempsey fired home the winner on a late free kick.

That 86th-minute strike from Dempsey was not only beneficial to the Sounders because it put them ahead in the series, but also because it gave the striker more confidence. Dempsey had been criticized in recent weeks and months for a noticeable dip in performance, but he is now returning on a good run of form after scoring four goals in his club’s last three games.

Those numbers are reminiscent to the unworldly ones he was putting up at the start of 2015, and that’s part of the reason why the Sounders are looking more and more like a serious contender again in the West.

“I think for Clint it’s just about being healthy and it’s the healthiest he’s felt in a while,” said Schmid. “I think the Gold Cup is, psychologically, very draining. It’s a draining time for the U.S. (Men’s National Team) because they didn’t do as well as they would have wanted to. The hamstring injury (that followed), obviously physiologically, was hard for him as well and all the other stuff that went on during the summer.

“He sort of had to come out of that valley and I think he’s out of that valley. He’s been scoring goals for us, getting early goals for us as well in games, he continues to combine well with Oba. Keeping Clint fresh and healthy is the key thing.”

Another aspect that will potentially determine the outcome of this second leg and series is how the Sounders fare in the midfield. Osvaldo Alonso is still a question mark due to injury, and not having him again would be a big blow for Schmid’s side given that FC Dallas is expected to play a little more aggressively this time around.

The Sounders still see some areas where they can exploit FC Dallas should the hosts come out on the front foot a little more than they did in Seattle.

“That takes away a little bit from their strength, which their strength is you attacking them and them countering on you,” said Schmid. “How Oscar is going to find that balance is really probably his test for this game, and for us, it’s a matter of making sure we find the balance of making sure we defend with security but also that we attack with good numbers.”

Some observers might compare this series to the one the two clubs had in the Western Conference semifinals in the 2014 MLS Playoffs . The Sounders prevailed last year due to the away-goal rule on a 1-1 aggregate score, but history cannot identically repeat itself this time given the 2-1 result of the first leg last Sunday.

FC Dallas has to triumph in order to advance. The Sounders do not, but they think the best approach is to go out with that mindset anyway and let the chips fall where they may.

“The loss doesn’t benefit either of us. That’s something that’s already been written for this series,” said Pareja. “Dallas isn’t a team that tries to play for a draw, especially not at home, so we’re going to go out to try and win the game like always. I think everything is there for us to do well and advance from the series.”

Said Schmid: “We’re going into the game to try and win. When you go in trying to win, if you end up getting a tie you’re happy. Sometimes you go in trying to get a tie, and it doesn’t always work out the way you want it to. We plan on scoring at least one goal down there, so we don’t think the away goal is going to affect.”