Sunday will see another edition of the biggest rivalry in MLS – Portland vs. Seattle – for the first time this season. And it will be televised nationally (3 pm ET on FOX, MLS LIVE in Canada), so there's no excuse for anyone to miss it.

This time, you definitely don't want to miss it, because despite the fact that the game is simply a mid-season, midsummer meeting, the result matters even more. To both teams.

Here’s a prediction: Whoever wins on Sunday will embark on a season-defining run that will pull them up from their lowly spots.

Odds are it will be the hosts, Portland, though I wouldn’t put money on that.

Right now, the Timbers are just outside the playoff spots, in seventh place in the Western Conference. Not a big deal, right? After all, they are the defending MLS Cup champs. They have lots of talent, from US national team player Darlington Nagbe to Nigerian goal beast Fanendo Adi to the veteran redwoods in the back, Nat Borchers and Liam Ridgwell. And they still have 14 games to play.

But let’s be honest: The Timbers have been less dominant in matches and they have a total of eight total draws, tied for second most in MLS.

But if you look at things a little more, you see they aren’t in the dire straits it might seem they are. For one, they are awesome at Providence Park (6-2-2 record, 20 of 30 available points). And if you take a longer look at their recent record, you see they are riding an eight-game unbeaten streak (3W, 0L, 5D).

Meanwhile, as any MLS observer will tell you, the Sounders possessed the statistically most anemic offense in the league. And yet it boosted them out of last place in the league on Wednesday night – a 5-0 whitewashing of league leaders FC Dallas.

“It lifts the spirits a bit,” Sounders captain Brad Evans said. “Now we’ve got a taste of victory and hopefully we can start to get consecutive results and start to pick up some points and make up some ground.”

But, as so often seems to be the case with Sounders on the field, there are caveats. Star striker Clint Dempsey will miss the Timbers match after receiving his first career MLS red card against FC Dallas.

So, without Deuce, Seattle’s attacking burden falls squarely on the shoulders of rookie Jordan Morris, who has seven goals on the season heading into his first Portland-Seattle match.

What better time for Morris to stamp his name into Pacific Northwest soccer lore than against the Timbers on Sunday?