The Philadelphia Union and New England Revolution will begin their best-of-three MLS Cup Playoff first-round series on Saturday in Southeast Pennsylvania armed with plenty of recent knowledge about their opponents.

New England defeated Philadelphia 2-1 at home on Oct. 21, the final day of the regular season, to split the regular-season series and move into a virtual tie on points for fourth place in the Eastern Conference

The Union kept a hold of the fourth seed via a superior goal differential (plus-16 to plus-12). But for a New England side that has endured the controversial investigation of — and subsequent resignation by — former manager Bruce Arena, it was a confidence-building result following some late-season struggles.

Clint Peay, the team’s second interim manager of the season, returned to a 4-2-3-1 formation after tinkering with a three-center-back system several times in previous games. And Gustavo Bou scored his sixth and seventh goals of the campaign to snap an injury-plagued drought that had extended back to July.

“It felt like us — getting after the ball, pressing, and then defending really narrow and condensed at times,” Revolution midfielder Matt Polster said. “We were able to break and score the second goal that way, so it just felt more of what we were used to.”

The Union, the defending Eastern Conference champions, will have to be defeated at least once at home if the Revs are to prevent them from reaching a third consecutive conference final.

Philadelphia has won its last two at home against New England and had staked itself to an early lead on Saturday through Julian Carranza’s 14th goal of the season, pulling the Argentine level with Daniel Gazdag for the team scoring lead.

The game was nearly even statistically from open play, with the lone penalty kick earned by New England and converted by Bou proving the difference.

Even so, this will be a new experience even for a seasoned playoff side like the Union, who have qualified for six consecutive playoff appearances.

“Of course, it’s a bit of a special situation,” forward Mikael Uhre said. “I don’t think I’ve ever played the same team possibly four times in a row. I think last time we saw some things we could improve, some places where we could hit them. So it’s about fine-tuning that in this week and then get a good result on Saturday.”

–Field Level Media