After the interruption of the international break, the Major League Soccer playoffs will resume in earnest this weekend with the two Conference finals first legs. In the East, the Columbus Crew will host Supporters Shield winners the New York Red Bulls, while in the West FC Dallas will travel to the Portland Timbers.

Here’s what to watch for as the final four play for a berth in MLS Cup 2015.

Columbus Crew vs. New York Red Bulls (First leg: Sunday, 5 p.m. EST, ESPN, ESPN Deportes)

The Red Bulls were business-like rather than spectacular in getting through the previous round of the playoffs against rivals DC United. A 2-0 aggregate victory failed to see Jesse Marsch’s side performing at the intense peak they so often reached throughout the regular season, but a set-piece goal in the nation’s capital followed by a late breakaway goal from Bradley Wright-Phillips at Red Bull Arena saw the No. 1 seeds safely through. And Marsch will care little about the performance with the focus firmly on the quest to bring a long-sought first MLS Cup title to New York. Being able to field a remarkably consistent lineup throughout the season has been key to New York’s success and there should be little disruption for Sunday’s first leg. Only two likely starters -- Matt Miazga and Kenmar Lawrence -- were away with their national teams, and even then only in the Concacaf region.

New York’s opponents could suffer more from the international layoff. Defender Harrison Afful and midfielder Cedric Mabwati have both been in Africa, while forward Justin Meram has had to travel back from Taiwan, where he was with the Iraq national team. For coach Gregg Berhalter, there will also be a need to avoid a letdown after progressing to the finals in dramatic circumstances. Columbus, which finished seven points behind the Red Bulls in the regular season, fought back from a 2-1 loss in the first leg to the Montreal Impact to edge through in extra time. Once again it was Kei Kamara, scorer of 22 goals in the regular season, who was the hero, coming up with the winning goal with a trademark header. In the regular season, the Red Bulls had the edge, winning two of the teams’ three contests, but Columbus triumphed in the clubs’ most important ever meeting, in the 2008 MLS Cup final.

Prediction: New York Red Bulls to advance

Portland Timbers vs. FC Dallas (First leg: Sunday, 7:30 p.m. EST, Fox Sports 1, Fox Deportes)

The big names in the West have been cast aside, with five-time MLS Cup winners the LA Galaxy and Clint Dempsey’s Seattle Sounders seeing their seasons brought to an early end. Indeed it was Dallas that accounted for the Sounders, with a thrilling victory in the Conference semifinals. In an incredible climax to regulation time in the second leg, Dallas was out, then in, then out again before an injury-time goal from Walker Zimmerman secured extra time and eventually a penalty shootout victory. It was a true victory for youth over experience, with coach Óscar Pareja continuing to brilliantly marshal a lineup with an average age of just 24.5. The pick of the bunch has been 23-year-old Colombian Fabián Castillo, who has 10 goals and seven assists this season.

Dallas finished seven points better off during the regular season, but it will now have to get past a Portland Timbers team in a rich vein of form. Throughout the season Portland’s form has gone in waves, with a woeful set of results toward the end of the campaign threatening to cost the team a playoff place. But Caleb Porter’s side finished the season with three straight victories and they have continued that momentum into the playoffs, knocking out Sporting KC and then the second-seeded Vancouver Whitecaps. And in Darlington Nagbe they have a key player who should be only invigorated by the international break, having made his debut for the United States. In the regular season, the series was split, with both Portland and Dallas recording convincing home wins.

Prediction: FC Dallas to advance