WITH THE U.S. NATIONAL TEAM claiming players early in preparation for the CONCACAF Gold Cup, several MLS sides will be without key figures this weekend.

How those clubs replace their starters will be a major talking point in Week 18.

For example, Sporting Kansas City will be without a star trio for an appetizing home game with the Portland Timbers on Saturday. U.S. coach Bruce Arena summoned Matt Besler, Graham Zusi, and Dom Dwyer for the regional tournament, leaving first-place Sporting KC a bit shorthanded as it attempts to create more distance between itself and the rest of the west.

The good news for Sporting KC is that Arena did not call in athletic centerback Ike Opara, who is doing it all these days for his club. Apart from helping lead the stingiest back line in the league, Opara has started to find the back of the net. He now has three goals in his last five games across all competitions, and is playing at a level that warrants not only a national team look but also MLS MVP discussion.

FC Dallas finds itself short-staffed as well. Kellyn Acosta and Matt Hedges were among the 23 players selected by Arena, and their absences make for big losses ahead of a home encounter against a Toronto FC side that will have Michael Bradley, Jozy Altidore, and Sebastian Giovinco all available.

D.C. United will also feel the affects of July’s Gold Cup, as it will not have Bill Hamid in goal this weekend for its trip to Montreal. Normally, that would be bad news on its own, but it is even worse for lowly D.C. because it regularly needs strong play between the pipes to have a chance at pulling out a result. Last night's NYCFC-Minnesota tiled demonstrated how a seldom-used back-up goalkeeper can negatively affect a game.

Too easy. @Chris_Ramirez17 gets number ???? on the season! #NYCvMIN https://t.co/jqVc9qEZAM

— Major League Soccer (@MLS) June 29, 2017

D.C. United will be hoping No. 2 Travis Worra can stay tidy in the back.

WHERE WERE YOU LAST WEEK?

MLS Rivalry Week took place this past weekend, yet somehow one of the more exciting rivalries in the league was scheduled for this Saturday. It comes with an interesting twist, too.

The second edition of the Cali Clasico in 2017 will take place on Saturday night, as the San Jose Earthquakes welcome the LA Galaxy to Stanford Stadium. San Jose will be playing its first game since canning head coach Dominic Kinnear earlier this week, and how the team responds under interim boss Chris Leitch bears watching.

#Quakes74 part ways with head coach Dominic Kinnear and assistant coach John Spencer: https://t.co/3pJvuBvEDm pic.twitter.com/T1pRfoMalA

— San Jose Earthquakes (@SJEarthquakes) June 25, 2017

Of course, the Earthquakes will want to make amends for its home loss against the Galaxy the last time out. Los Angeles marched into Avaya Stadium a month ago and posted an impressive 4-2 victory in a thrilling encounter that saw Giovani dos Santos bag a brace. The 28-year-old dos Santos will not be around this time, however, so the Galaxy need to find someone else to make the difference while he continues to represent Mexico at the Confederations Cup in Russia.

Coincidentally, both the Earthquakes and Galaxy head into this 64th chapter of their rivalry with midweek U.S. Open Cup wins and an extreme desire for three points. San Jose and LA have won just once in their last four league matches and need to prevail in order to avoid potentially slipping under the red line in the Western Conference. The Earthquakes and Galaxy are currently in fifth and sixth place, respectively, and the Vancouver Whitecaps and Seattle Sounders are within striking distance.

While playing a team filled with players trying to make a good first impression with its new manager can prove difficult, LA is without a doubt the best road team in MLS this season, amassing a 5-2-1 record away from StubHub Center. In Carson, however, the team is just 1-4-3.

San Jose, meanwhile, needs to score some goals. The Earthquakes have netted just 18 times through the first half of the 2017 campaign. (We're looking at you, Chris Wondolowski.)

FEELING HOT, HOT, HOT

If there is one player to watch in all of this weekend’s MLS action, it might just be Columbus Crew playmaker Federico Higuain.

Currently on a four-game scoring streak that has seen him net five goals and assist on another, Higuain will lead Columbus into battle against high-flying Atlanta United. The match-up on its own is compelling given how attack-minded Eastern Conference squads are this season, but it is made all the more appealing with Higuain playing at such a high level.

The skillful Argentine’s brace against Montreal last week helped Crew SC post a 4-1 win, and gave him nine tallies on the year to go along with five assists. There had been talk during the offseason that Higuain, 32, was over the hill, but he is currently on pace to outdo even his best seasons in MLS from 2013 and 2014.

TAKE FRIDAY OFF, MLS PEOPLE

Fourth of July is just around the corner, but do not feel reluctant to start your festivities early—particularly on Friday night.

One MLS game is on tap for Friday, and it's not exactly appointment TV. Real Salt Lake is set to host Orlando City at Rio Tinto Stadium, but neither side heads into this showdown in a good way. RSL has just two wins in its last six outings while Orlando has hit a major bump in the road and prevailed once in its last 11 games.

The Lions could have star striker Cyle Larin back for the first time since he was arrested on a DUI charge earlier this month, but even that is not enough to make this a worthwhile watch. Skip it.

MLS WEEK 18 SCHEDULE

Friday’s MLS Game
Real Salt Lake vs. Orlando City

Saturday’s MLS Games
Chicago vs. Vancouver Whitecaps
FC Dallas vs. Toronto FC
Sporting Kansas City vs. Portland Timbers
Montreal Impact vs. D.C. United
Columbus Crew SC vs. Atlanta United
Colorado Rapids vs. Houston Dynamo
San Jose Earthquakes vs. LA Galaxy

Sunday’s MLS Games
Philadelphia Union vs. New England Revolution

Franco Panizo is a bilingual New York-based reporter who has covered the U.S. men's national team, MLS, and all levels of American soccer for nearly a decade. Follow him on Twitter.