The last lower-division team standing in the 2025 Lamar Hunt U.S. Open Cup, Pittsburgh Riverhounds SC will attempt to reach the Quarterfinals for the second time in three seasons on Wednesday night.

Standing in their way? A Philadelphia Union side which has reached the Open Cup Final three times previously in its history and that currently sits top of Major League Soccer’s Eastern Conference with a 9-3-2 record.

As the Hounds head east to Subaru Park for their first official meeting with their Keystone State rival, here are four things you should know ahead of the 7:30 p.m. ET kickoff on Paramount+.

1. History doesn’t always repeat, but it can rhyme

If there’s one thing the current Hounds have going for them, it’s that they’ve accomplished this before. Two seasons ago the side headed to face the New England Revolution – at the time sitting in first place in MLS’s Eastern Conference with only one defeat in its first 11 games – in the Round of 32 and advanced with a 1-0 result via a first-half goal by Danny Griffin at Foxborough Stadium.

While there’s been plenty of change in Pittsburgh’s squad since then, there are still four players from that lineup – Griffin, Robbie Mertz, Junior Etou and Luke Biasi – who remain with the club. For that group, and those who got their first taste of a Cupset against New York City FC on May 7, believing a result is possible is crucial, even against a team with the Union’s impressive current record.

“I think the Revs were flying high at the time in MLS,” Mertz told CBS Sports Golazo’s Tony Meola and Benny Feilhaber. “They might have been top of the east at that point, and we were able to go into Gillette and beat them there and then get a win at home against Columbus as well.

“So, I think it’s something that we believe we’re capable of. We’ll just try to take that mentality that we don't really have much to lose in this in this match-up, so [we can] just kind of lay it on the line and see what happens.”

2. Find the balance between playing free and in control

Mertz’s sentiment that the Hounds don’t really have anything to lose coming into Subaru Park is one Philadelphia Union Head Coach Bradley Carnell feels as well.

“In some sense you can always play free as the underdog,” he said at his Tuesday press conference. “You have no pressure, and I think that’s the way they’re going to come out tomorrow. They’re going to try and continue their journey, and they’re proud of that journey so far.”

Going back two seasons, that was certainly the case for the Hounds then. What was striking about each of their victories against the Revolution and a Columbus Crew side which went on to win MLS Cup later that year was the way the side was able to dictate the areas the game was played. Pittsburgh had a scant 25 percent of possession in its 1-0 victory against the Crew at Highmark Stadium, but only 20.3% of the game was played in its defensive third, and Columbus had only eight touches inside the penalty area.

Finding that level of freeness and confidence with the discipline to match is a tricky balance to pull off. It’s notable the best chance New York City FC had against the Hounds two weeks ago came after it was reduced to 10 players. With four minutes to go, Julián Fernández sent a glorious finish wide from a well-worked counterattack as the visitors caught the Hounds off-guard.

As good as the Union have been this season, Pittsburgh can’t offer those sorts of gilt-edged chances this time and hope not to pay the price.

3. The opening goal is as important as ever

If you needed an example of how important the opening goal can be in a knockout competition, you need only look at the prior rounds of this year’s U.S. Open Cup. So far, the clubs that score the opening goal are 66-12 in terms of advancing, with two scoreless draws through 120 minutes having also occurred. That includes a 15-1 mark in the Round of 32, when only Austin FC advanced after conceding the opening goal against the Championship’s El Paso Locomotive FC.

That’s a potential challenge for the Hounds, who have been up-and-down when it comes to starting games this season. The side has yet to score in the opening half-hour of a game in the USL Championship – the earliest the side has scored in all competitions was Danny Griffin’s 28th-minute goal that served as the winner in a 1-0 win against the Columbus Crew 2 in the Third Round of the Open Cup. Facing a Philadelphia Union side that jumped up early against Indy Eleven last round before advancing in a penalty shootout, the Hounds will need to find the right level of energy to take on their top-flight opponent.

4. Don’t bank on the Union’s rotations diminishing their quality

The headline to the Philadelphia Union’s Open Cup clash two weeks ago was the first start in the club’s colors of Cavan Sullivan, the uber-talented 15-year-old for whom there’s already a deal in place for a transfer to the Premier League’s Manchester City when he turns 18.

But while there were current rotational players – of which Sullivan is one for the moment – in the Union’s lineup against Indy, the balance Carnell struck was the sort of a manager who wants his side to keep progressing in this tournament. On one hand there were players like Jeremy Rafanello going the full 120 minutes – 92 more than he’s recorded so far in MLS this season – but on the other he was joined in the starting lineup by the club’s minutes leader in Jakob Glesnes. When he came off at halftime, his replacement was Nathan Harriell, who on Monday was in the United States’ preliminary 60-player roster for the 2025 Concacaf Gold Cup.

Also starting that night? Forward Bruno Damiani, who currently sits third in Goals Added for the Union this season at a +3.36 mark. While top talents Mikael Uhre and Quinn Sullivan were given the night off, there was more than enough for Philadelphia to tap into and move on.

There’s been a balancing act for Carnell to achieve this month – the game against the Hounds will be Philadelphia’s sixth in 19 days across all competitions with three more on tap before the end of the month – and his rotations have been used to try and keep his team fresh and healthy.

That’s a potential plus for the Hounds, who can be free to choose the lineup that gives them the best chance to advance, but they’re unlikely to get many favors when it comes to the lineup from their in-state foe.