MLS Conference Semifinals: Key Injuries, Another Baseball Stadium and El Trafico

The rapid sprint that is the MLS playoffs continues this week, with four conference semifinal clashes.

There's little rest for MLS's playoff teams–at least the ones that played over the weekend–with the conference semifinals picking up with a pair of midweek doubleheaders. 

NYCFC hosts Toronto FC, while the Seattle Sounders welcome Real Salt Lake to the Pacific Northwest on Wednesday night. That's followed by Atlanta United hosting the Philadelphia Union and LAFC taking on the LA Galaxy in the most anticipated edition of El Trafico yet.

Here's a closer look at all four matchups (all times Eastern):

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NYCFC vs. Toronto FC

Wednesday, 7 p.m. | Toronto FC won 4-0, teams tied 1-1 in regular season

This matchup pits the East's two most in-form teams against one another at Citi Field, in what's technically a home match for NYCFC even though it was forced to sub one baseball stadium out for another due to conflict with the Yankees' playoff schedule.

NYCFC has one loss in its last 11 games, while Toronto FC is unbeaten in 11, including Saturday night's extra-time explosion vs. D.C. United. Their season series is a little misleading, given that NYCFC didn't have Maxi Moralez or Heber available for either matchup. Those are only two of NYCFC's most influential players, with Moralez the league leader in assists with 20 and Heber the club's leading scorer with 15. 

Their returns make it all the more important for Toronto that Jozy Altidore and Omar Gonzalez are available for selection after being forced to miss the 5-1 win over D.C. That scoreline was awfully generous and a product of an extra-time capitulation, and while being shorthanded against D.C. is one thing, doing so and finding success against NYCFC is entirely another. Altidore being able to occupy NYCFC's defense and Gonzalez being able to put out fires in the back are two key components of this matchup, provided both can play.

If there's one thing to take from their regular-season matchups, it was the success of Toronto DP Alejandro Pozuelo, who combined for three goals and an assist and figures to be at the center of it all once again.

Seattle Sounders vs. Real Salt Lake

Wednesday, 10 p.m. | Seattle won 1-0, RSL won 3-0 in regular season

Both enjoyed some playoff drama en route to advancing, with Seattle outlasting FC Dallas in a seven-goal, extra-time thriller, while RSL needed a late winner to oust Portland.

There's some symmetry in this match for RSL stalwarts Nick Rimando and Kyle Beckerman, who were part of the 2009 team that beat the LA Galaxy in Seattle to win MLS Cup a decade ago. Now they return, playing on considerably older legs with the same, influential responsibilities. Beckerman will be tasked with slowing down Nicolas Lodeiro and an explosive Sounders midfield, while Rimando will be the last line of defense against the in-form Jordan Morris and Raul Ruidiaz.

Home field figures to be a big factor for the Sounders, but their defending–on set pieces, especially–leaves them vulnerable to a multi-pronged attack that doesn't have one go-to option but features threats from all over. In that regard, RSL is similar to Dallas–a side with some high-priced and veteran talent but also driven by its homegrown products.

Atlanta United vs. Philadelphia Union

Thursday, 8 p.m. | Teams tied 1-1, Philadelphia won 3-1 in regular season

The defending champions passed their first test, but they lost another key piece in the process. Michael Parkhurst's shoulder injury, on the heels of Miles Robinson's hamstring pull on international duty, puts Florentin Pogba in the spotlight across Frank de Boer's back line. The Atlanta Journal-Constitution reported that neither Parkhurst nor Robinson trained on Monday, making it all the more likely that Pogba gets the start.

Where Atlanta could have the advantage, aside from getting to play at home, is in terms of having slightly fresher legs. Whereas Atlanta played in the opening match of the first round and got the job done in regulation, the Union played more than a day later and was forced to expend tons of energy in clawing back from two goals down and playing an added 30 minutes in extra time. Perhaps playoff adrenaline takes over and mitigates that factor, but it's worth watching.

LAFC vs. LA Galaxy

Thursday, 10:30 p.m. | Galaxy won 3-2, teams tied 3-3 in regular season

LAFC is hoping to cap its historic season with a title, but it'll need to do something it's never done in five tries, and that's beat the crosstown Galaxy.

This matchup has been known to be synonymous with drama, action and goals, and that's reflected in the secondary market, where ticket prices are reportedly soaring for fans hoping to catch a glimpse of what's rapidly become MLS's best head-to-head matchup.

Zlatan Ibrahimovic has been an unsolvable problem for LAFC over the course of two seasons, but he was uncharacteristically unspectacular on a big stage for the Galaxy Sunday night in Minnesota. This matchup seems to bring the best out of him, between his debut fireworks, his hat trick in the first meeting between the two sides and his double in the draw at Banc of California Stadium. A second straight playoff dud seems unlikely.

On the flip side, there's the very rested Supporters' Shield holders, who will have gone 18 days in between games. League MVP-in-waiting Carlos Vela will be ready to go toe-to-toe with Ibra, though it's unclear if midfield cog Mark-Anthony Kaye will be fit after injuring his hamstring early in Canada's win over the USA. Walker Zimmerman, who suffered a concussion on Decision Day, and Adama Diomande, who had been in the league's substance abuse and behavioral health program, are good to go.

This match will be filled with emotion, and there's pressure on both sides. LAFC is facing its bogeyman club with title-or-bust expectations, while the Galaxy know that it could wind up going trophy-less in two seasons with Ibrahimovic unless it can push forward. Expect anything and everything in this round-capper.