Two teams surging in California, two others struggling for consistency in Canada, two more set for a brutal fight for the top spot in the East, and the best rivalry in MLS featuring an added dose of desperation.

MLS rivalry week isn't lacking for storylines and the league has put together a menu of action that could be the best weekend of action we will see until the playoffs.

The high-profile clashes are spread out across the continent, from California to New York, Toronto to Seattle, and if the rivalries didn't already bring enough to the table, all four matches have serious implications in the playoff chase as we draw closer to the final stretch of the regular season.

But the Week 26 storylines don't just involve the rivalry games. In New York, David Villa will look to help NYCFC recover from last week's embarrassing loss to the Galaxy. In Orlando, Kaka will try to help Orlando City avoid a third straight bad loss, with the Chicago Fire looking to build on a surprising midweek win against the New York Red Bulls.

Philadelphia plays host to New England in a match that won't receive much hype, but that could impact the chase for the final playoff spots in the East. The Revolution will be aiming to jump into a top three spot in the East standings, while the Union try to build on the momentum from last week's win in Montreal to climb closer to a postseason spot.

Those matches are very much the undercard in a weekend with several high-profile matchups. Here is a look at the five things to watch for in MLS Week 26:

HOW WILL GIO DOS SANTOS RESPOND TO MEXICO SNUB?

The Galaxy and Earthquakes already had plenty of storylines to follow heading into Friday night's match, but when Giovani dos Santos was left off Mexico's roster for its upcoming friendlies, we were suddenly left wondering just how the Mexican playmaker would respond. The snub might spell bad news for an Earthquakes side that needs a victory to draw closer to a playoff spot.

The Earthquakes are the underdogs, but after beating top contenders Sporting Kansas City and D.C. United in consecutive road games, Dom Kinnear's side suddenly looks capable of giving anybody trouble. The work of their midfield has been particularly impressive, but Shea Salinas and Cordell Cato may find the going tougher against Galaxy fullbacks Robbie Rogers and A.J. De La Garza.

Conversely, Galaxy wingers Sebastian Lletget and Gyasi Zardes have been flourishing in the space being created by Robbie Keane and Dos Santos, and the Earthquakes may become the latest team to struggle to contain them. It was only a month ago that the Galaxy tore through the Earthquakes in a 5-2 victory at home. LA will be favored to win again, but being on the road, and facing a confident Earthquakes team, should make it a much tougher test this time around.

CANADIAN DERBY OFFERS DROGBA ANOTHER CHANCE TO IMPRESS

As far as debuts go, Didier Drogba's Montreal Impact debut was pretty tame. Thirty minutes, two shots, no goals, and the team eventually lost to the Philadelphia Union. A few days later, Drogba was held out of the decisive Canadian Championship match against the Vancouver Whitecaps, which the Impact went on to lose (Montreal officials cited a nagging toe injury).

Not exactly the start Impact fans were hoping for when Montreal signed the former Chelsea star. That disappointing start will quickly be forgotten if Drogba can make his mark on this weekend's Canadian derby between the Impact and Toronto FC. He did show some flashes in his debut, and Toronto's defense hasn't exactly been stingy this year.

We could end up seeing plenty of goals at BMO Field, particularly if Sebastian Giovinco is provided with the kind of support he received last week. The Italian sensation worked well operating as the lone forward, with Jozy Altidore benched. Will Greg Vanney keep Altidore out of the starting lineup, or will he see the two late goals Altidore scored last week as evidence that the U.S. striker is ready to go on a tear?

EAST LEADERS LIMP INTO I-95 DERBY

D.C. United and the Red Bulls have been sitting on the top of the Eastern Conference standings for some time now, and their showdown at Red Bull Arena on Sunday had been circled on calendars for a while. So why do both teams head into the I-95 Derby having suffered lackluster losses? Were the teams looking ahead to Sunday?

Despite the fact both teams suffered recent losses, Sunday's match shoould still be intense and filled with fireworks. The Red Bulls thoroughly dominated D.C. United the last time these teams met at Red Bull Arena, though that was way back in March. Ben Olsen is sure to remind his team of that match, and also the fact D.C. hasn't beaten the Red Bulls yet this year. If D.C. is going to earn the road win, Alvaro Saborio will need to pick up the scoring slack left by the injury to Fabian Espindola, and the midfield will need to play significantly better than it did in the 2-0 loss to San Jose last Saturday.

The Red Bulls didn't exactly shine in their last match either, dropping a 3-2 decision to the lowly Chicago Fire. The midfield was uncharacteristically sloppy, and Jesse Marsch may have to think about handing Shaun Wright-Phillips and/or Gonzalo Veron their first start for the Red Bulls. San Jose had success troubling D.C. on the flanks with speed. Veron and Lloyd Sam would create a speedy flank pairing that could help the Red Bulls find the soft spots in the D.C. defense.

TIMBERS AND SOUNDERS FEELING THE HEAT

Seattle's 2-0 loss to Real Salt Lake had to set off alarm bells among Sounders fans. This was, after all, just the kind of flat performance we weren't supposed to see anymore after the handful of key acquisitions in the summer window. Unfortunately for the Sounders it did, and now Sigi Schmid's side is finding its margin for error shrinking.

The good news for the Sounders is that they're back home, with a full CenturyLink Field expected for the latest installment of the Cascadia Derby with the Portland Timbers, widely regarded as the best rivalry in MLS. Seattle will need the support of the more than 63,000 expected to attend Sunday's match, but more importantly, they will need more production from an attack that mustered just one shot on goal in last week's 2-0 loss to Real Salt Lake. It is unclear whether Clint Dempsey is recovered from the hamstring injury that had him sidelined, but even without the U.S. star, the Sounders should have enough firepower with Obafemi Martins and newly acquired Nelson Valdez and Andreas Ivanschitz.

For the Timbers, finishing chances has been a consistent sore spot, and a reason why they had to play catch-up in last week's 2-2 tie with Houston. Newly acquired Designated Player Lucas Melano enjoyed a breakout match against the Dynamo, and Caleb Porter will need the Argentinian speedster to work his magic to break down the imposing Sounders central defense tandem of Chad Marshall and Roman Torres.

WILL DAVID VILLA'S WORDS INSPIRE NYCFC?

You couldn't really blame David Villa for feeling frustrated after watching his team suffer a 5-1 drubbing against the LA Galaxy, but it was still somewhat surprising to hear him publicly lament the lack of support he's been getting from his teammates. "I can't do it alone," was Villa's message, and we will find out this weekend how his teammates receive that message.

NYCFC returns to the comfy confines of Yankee Stadium on Saturday, when the club will face a dangerous Columbus Crew side led by the dynamic duo of Kei Kamara and Ethan Finlay, who have combined for 26 goals and 20 assists this season. Perhaps Villa's frustrations came from last week's meeting with the Crew, when he watched Kamara receive such good support from Finlay and Federico Higuain.

Villa isn't exactly alone on NYCFC. Kwadwo Poku has enjoyed a breakout summer, and is proving to be a handful for opposing defenses. What both Villa and Poku need are for the NYCFC midfield to provide more service so that Villa and Poku aren't left to try and create on their own. If Villa's plea for help is heard, we could be in for a goal-fest on Saturday. If not, NYCFC could take another step toward missing the playoffs.