Craig Mitchelldyer/Portland Timbers

For a third year in a row, the Portland Timbers have had a frustrating spring. But beyond the numbers—12 points from their first twelve games for a lowly ninth place in the Western Conference—there is cause for alarm.

The Timbers haven't kept a clean-sheet all season, shipping a league-worst 22 goals. Beyond that, two hallmarks of the Caleb Porter Timbers—strength on the road and strength after losses—have disappeared. Portland hasn't won away from home all season, and has lost three consecutive games for the first time since 2012. What's more, if the Dairon Asprilla situation is any indication, all is not well behind the scenes.

Considering the trajectory of the last season, it's not yet time to panic. But any way you slice it, Sunday's Cascadia Cup home match against Vancouver (2 pm, ESPN) is a big one.

The History

The Timbers' recent three-game slide started two Saturdays ago in Vancouver. Portland, coming off a marquee home win against Toronto, took a 1-0 lead into halftime only to let it slip and lose 2-1.

It was a turning point. Not just for the Timbers, but also for the Whitecaps. Carl Robinson's team struggled mightily—especially offensively—out of the gates this season, but followed up the success against Portland with thrilling victories over Chicago and Toronto. As a result, the 'Caps have skipped into third place in the West.

Vancouver proved a difficult team for the Timbers to crack at home last season, playing Portland to 0-0 and 1-1 draws in the regular season, and then another 0-0 draw in the first leg of the Western Conference Semifinals in November.

There has been some debate in the buildup to the game on Sunday over the nature of the rivalry between the two clubs. Just look at the different ways the teams' websites covered the story this week. In a nutshell, it's a duel that means more to Vancouver than it does to Portland.

The Tactics

Porter will get a boost in the return of Diego Chara on Sunday, but a bigger concern is the health of Fanendo Adi. The Nigerian striker, who is currently tied atop the MLS scoring charts with David Villa, had to come off against NYCFC last weekend after hurting his hamstring. His status for Vancouver is unknown.

If Adi can't start, Jack McInerney should get the nod in his place with Darren Mattocks out injured. Porter opted to play 4-2-3-1 against NYC, and he could use the same formation against Vancouver with Chara sliding in for Ben Zemanski next to Jack Jewsbury.

At this point, with Asprilla on the fritz, it's difficult to find two wingers good enough to support Porter's preferred 4-3-3. That also means that despite his awful performances over the past weeks, there is no replacement for Lucas Melano. The Timbers just need their $5 million man to play better.

The coach also has a decision to make at left-back, where Jermaine Taylor started and impressed in place of Chris Klute last weekend.

Vancouver will be without a fullback of their own, as Frasier Aird was sent off against Toronto. But Aird has been a liability when he's played this season, so it could be a blessing in disguise for Vancouver—who should be able to reunite their top center-back pairing of Kendall Waston and Tim Parker for the first time since the Timbers visit to BC Place.

Kekuta Manneh is the danger man for the 'Caps, who could, with very limited options, start Beaverton native Erik Hurtado up top. Pedro Morales, who is finally beginning to excel in a deeper midfield position, is another player to watch.

The Lineup

90 - Gleeson
16 - Valentin
24 - Ridgewell (C)
7 - Borchers
4 - Taylor
13 - Jewsbury
21 - Chara
6 - Nagbe
8 - Valeri
26 - Melano
99 - McInerney

The Pick

The Timbers were close to breaking through against NYCFC, and, with little bit of refereeing luck, easily could have won that game. With Portland having lost three straight, and the 'Caps having won three straight, it makes perfect MLS sense that the Timbers will win on Sunday by two goals to one.