MLS Week 19 Preview: Contending the Cascadia Cup as Chelsea stars reunite

Week 19 of the 2016 MLS season gives fans another full slate of matches to enjoy, with 12 teams competing midweek before returning to action over the weekend.

Here are three matchups worth watching in Week 19:

The Chelsea reunion show

Fans of English outfit Chelsea will want to tune into Sunday night's clash between the Montreal Impact and New York City FC as club icons Didier Drogba and Frank Lampard square off at long last.

It's the first time these former Blues meet in Major League Soccer and the two close friends and longtime teammates won't hold anything back when the referee kicks things off at Stade Saputo.

Related - Lampard relishing Drogba reunion: 'I can't wait to play against him'

Lampard enters this fixture in fine form, having scored four goals in his last five games for NYCFC, while Impact striker Drogba comes in well-rested, having skipped out on the club's last fixture, but declared himself fit for this reunion match.

Cascadia Cup: Timbers vs. Sounders

The Portland Timbers host the Seattle Sounders at Providence Park on Sunday in the fourth of nine Cascadia Cup matches in the 2016 season, as these two bitter rivals face off for the first time this season.

We've already seen the Sounders drop the opening tilt against the Vancouver Whitecaps back in March, and the Canadian outfit also defeated the Timbers in May, before losing a return leg to Caleb Porter's side. And, while the Whitecaps sit atop the Cascadia Cup standings, that will change if the Timbers defeat the Sounders on Sunday.

This inner-league competition may feature three teams but there is no derby match quite as exciting in MLS as the one shared by Portland and Seattle. The 2015 MLS Cup-winning Timbers will go into this one motivated to succeed but Seattle has plenty of momentum after obliterating FC Dallas 5-0 on Wednesday night. Speaking of FC Dallas ...

First vs. Worst

Oscar Pareja's FC Dallas team is kind of tough to figure out.

On its day, Dallas is next to unstoppable, and the team sits first in the race for the MLS Supporters' Shield midway through the 2016 campaign. But, this is also a team evidently prone to the occasional 5-0 blowout - it's happened twice this season now.

In any case, Dallas will have a chance to turn around yet another massive upset when the team hosts last-place Chicago Fire on Saturday at Toyota Stadium.

While there are no guarantees in MLS, Dallas will certainly be relishing its chances against the Fire.

Perhaps the Hoops can deliver a 5-0 drubbing of its own.