The international break took its toll on several MLS teams, making for an unpredictable week 5 in Major League Soccer.
Injuries hit two of the hottest teams in MLS, as Josef Martinez and Romell Quioto are both sidelined, and will have to wait to build on their impressive starts to the season.
General fatigue could be an issue for players who played heavy minutes during the international break, such as Clint Dempsey, Roman Torres, Darlington Nagbe, Michael Bradley and Anibal Godoy.
As if all the travel being logged by national team regulars isn't enough, there are three matches featuring teams that will have made full cross-country trips, including New England, which visits Portland, and San Jose, which is at New York City FC this weekend.
This weekend could also bring us the debut of German World Cup winner Bastian Schweinsteiger, who joined the Chicago Fire this week and will finally be able to put his nightmare stint at Manchester United behind him.
If the international break has made you long for some good MLS action, the wait is a little shorter this week, as the two best matchups of this go-round are both being played on Friday night, as Atlanta United visits Seattle and Sporting Kansas City travels to BMO Field to play in Toronto FC's home opener.
Here is a closer look at the key talking points heading into MLS Week 5:
IT'S A BIG WEEKEND FOR ... TORONTO FC
The memories of last December's disappointing MLS Cup final defeat probably haven't faded much in Toronto, but the first step toward replacing those bad memories will start on Friday night, when Toronto FC plays its 2017 home opener at BMO Field against Sporting Kansas City.
Sebastian Giovinco is back from injury and U.S. national team stars Jozy Altidore and Michael Bradley return from international duty, giving Greg Vanney all his big guns for a match against a tough Sporting Kansas City side that should provide a very tough test.
TFC collected five points from three road matches to start the season, but will be hoping to build on the home momentum built in 2016, when the team's success led to larger crowds and a much better atmosphere at BMO Field.
Giovinco's return will bolster the Toronto attack, but TFC's success could hinge on how much Altidore has left in the tank after a taxing international break. Giovinco had a slow start to the 2017 before the injury, and will be looking to get started on his quest to add another MLS MVP to his trophy case. Sporting KC's defense will make it difficult on the Italian star, but the question for Peter Vermes' side will be if its attack can find goals against TFC's defense.
DON'T MISS ... SEATTLE SOUNDERS vs. ATLANTA UNITED
Atlanta United is one of the stories of the early season, with Gerardo Martino's squad exceeding the high expectations placed on the expansion side. We will now find out how Atlanta deals with adversity, as an already-tough trip to Seattle will be made tougher by the absence of star striker Josef Martinez to injury.
The Venezuelan striker was off to a fast start to his MLS career, but a quad injury will sideline Martinez for at least a month, forcing Martino to adapt. Kenwyne Jones figures to be the leading candidate to replace Martinez, but he just played 149 combined minutes for Trinidad and Tobago in World Cup qualifying action.
The Sounders figured to face their own issues coming off the international break considering the minutes logged by Clint Dempsey and Roman Torres, but both players were cleared to play in Friday's match, as was Jordan Morris, who has recovered from the ankle injury that kept him out of the U.S. national team's recent qualifiers.
If all hands are on deck for this one, the Sounders-Atlanta United clash is loaded with mouth-watering matchups. Osvaldo Alonso trying to corral Miguel Almiron will be must-see TV, and Greg Garza trying to slow down Nicolas Lodeiro will also be fun. A Torres-Kenwyne Jones rematch after the two went head-to-head last week in World Cup qualifying would be entertaining as well, along with Yamil Asad and Cristian Roldan trying to work their magic in central midfield.
Above all, Friday's clash in Seattle will offer Atlanta United a chance to show just how serious we should be taking the first-year team as a top contender. A win against the reigning champions would only add to the growing mystique surrounding the exciting new team.
MATCHUPS TO WATCH
Michael Bradley vs. Benny Feilhaber. With some fresh motivation after being left off the most recent U.S. squad, Feilhaber could send a strong message by outplaying his former Olympic and U.S. World Cup teammate.
Miguel Almiron vs. Osvaldo Alonso. Almiron looks capable of becoming the best playmaker in MLS, but first he must find a way around the irrepressible Alonso.
Sacha Kljestan vs. Ricardo Clark. The Red Bulls aren't going to hold back in their attack on the road, and it will be up to Clark to keep Kljestan from burning the Dynamo defense.
Gio Dos Santos vs. Matias Laba. A healthy Dos Santos could run wild in Vancouver, but not if Laba can keep him under wraps.
Nicolas Lodeiro vs. Greg Garza. If Jordan Morris and Clint Dempsey aren't 100 percent, the Sounders could be forced to lean on Lodeiro more than usual, and Garza will head into this one motivated to show Bruce Arena why he should be higher on the U.S. left back depth chart.
Ola Kamara vs. Jonathan Spector. Kamara is off to a fast start to 2017, but he'll face a player in Spector who has been excellent since joining Orlando City this season.
Jozy Altidore vs. Ike Opara. Altidore has been in good form for TFC, and his strength could cause some problems for Opara, but if there's someone who can handle Altidore's athleticism, it's Opara.
Maxi Moralez vs. Anibal Godoy. Will the heavy travel and national team minutes leave Godoy a step slow? If it does, Moralez could have a field day against the Earthquakes, though Fatai Alashe should help.
Kevin Molino vs. Kyle Beckerman. Molino looked good with Trinidad and Tobago during the international break, and should return to MLS with a boost in confidence. That could help the Loons earn their first MLS win unless Beckerman can contain the tricky midfielder.
Rodney Wallace vs. Nick Lima. Wallace didn't play a minute in either of Costa Rica's recent qualifiers, so he should be rested as he looks to continue his outstanding MLS by going at Lima, one of the early-season's most impressive rookies.
WEEK 5 PREDICTIONS
Toronto FC 2, Sporting Kansas City 0. Sebastian Giovinco's return helps propel TFC to a perfect homecoming at BMO Field.
Seattle Sounders 2, Atlanta United 1. A tough one to call given all the uncertainty surrounding the stars who were on international duty, but the Sounders have the edge at home, where Nicolas Lodeiro should outshine Miguel Almiron.
New York City FC 2, San Jose Earthquakes 0. After a disappointing draw before the international break, NYCFC returns to Yankee Stadium with a win against an Earthquakes side that finds the going tough away from home.
Chicago Fire 1, Montreal Impact 0. Bastian Schweinsteiger makes his MLS debut in winning fashion, as the Fire take advantage of a Piatti-less Impact.
Columbus Crew 2, Orlando City 0. The Crew keep the momentum going with a third straight win, as their midfield limits the service to Cyle Larin and Justin Meram and Federico Higuain do the rest.
D.C. United 1, Philadelphia Union 1. The good news for D.C. is a goal finally comes. The bad news is it's not enough to take all three points from the Union.
Minnesota United 2, Real Salt Lake 1.As much as the Loons might look capable of going winless for the year, a trip home against an RSL team in transition is just what Adrian Heath ordered.
Houston Dynamo 2, New York Red Bulls 1. No Romell Quioto? No problem, as the Dynamo still have enough weapons to cause problems for the Red Bulls, with Erick Torres leading the way.
Vancouver Whitecaps 1, LA Galaxy 2. Can the Galaxy win two road games in a row? Gio Dos Santos' return would be a big help, especially if the Whitecaps rest key starters ahead of their CONCACAF Champions League semifinal second leg against Tigres.
Portland Timbers 3, New England Revolution 1. Traveling across the country is tough enough, but having to endure that to then try and stop Portland's potent attack? That's too much to ask for as Diego Valeri keeps his hot streak going.