Denizens of opposite coasts, the Philadelphia Union and San Jose Earthquakes have nevertheless shared common ground for most of this decade.

San Jose's stirring 2012 Supporters' Shield triumph aside, the teams that will meet Saturday night at Talen Energy Stadium have been lodged firmly in Major League Soccer's middle class for a while now. Last year, they ranked side by side at Nos. 12 and 13 in the team-by-team payroll rankings as released by the players' union.

Neither of them has been all that bad, although the 2014 Quakes and 2015 Union were exceptions. Nor have they been very good, rarely intriguing enough to make any but the most loyal of die-hards pause while channel-surfing.

Philly made the postseason in 2016 but was eliminated in the knockout round; San Jose inexplicably snuck in last year with a negative-21 goal differential before getting routed 5-0 by Vancouver. The Earthquakes have managed just one series victory since returning to the Bay Area in 2008. The Union have yet to notch a playoff win.

Mostly, they've occupied the bland purgatory between MLS' contenders and the eye-catching dumpster fires. Each of them underlines how difficult it is to compete without the financial backing of the league's elite -- a challenge that grows more daunting by the year.

There was a time when success was not as tied to payroll as it is now. The 2006-07, back-to-back champion Houston Dynamo teams -- the core of which had relocated from San Jose -- was a great example of a squad that overachieved its raw talent, with pluck and spirit winning out over pedigree alone. Real Salt Lake, Columbus Crew SC and Sporting Kansas City followed similar models to win MLS Cups of their own in the following years.

The LA Galaxy's 2011 title feels like a turning point, in retrospect. The David Beckham era had yielded multiple first-places finishes but hadn't yet delivered silverware, a fact that was held up as proof that it took more than just big-name signings to win it all. Then the Galaxy won, in both '11 and '12 -- allowing Beckham to ride off into the sunset -- before lifting another in 2014.

The most ambitious of Major League Soccer's second wave of expansion teams, the Seattle Sounders and Toronto FC, finally turned their business-side achievements into on-the-field success, as well, reaching the most recent two MLS Cup finals and claiming one crown apiece.

San Jose and Philadelphia are becoming increasingly reliant on thrifty signings. Neville E. Guard-USA TODAY Sports

With each successive, aggressive expansion team, from Atlanta United to LAFC, the path toward contention gets tougher to map out for teams like the Earthquakes and Union.

Faced with increasingly long odds, San Jose has shaken up its own status quo. Longtime coach Dom Kinnear was dismissed in June. His interim replacement, Chris Leitch, helped lead the unlikely playoff push, and Swedish coach Mikael Stahre has taken over on a full-time basis. This is a club very much in flux.

Philadelphia's own philosophy is easier to pin down. If the Union's first few years of MLS existence were defined by cost-cutting, at least since Earnie Stewart took over as sporting director at the beginning of 2016, they have prioritized bulking up their youth academy. That might just be another way to tamp down on incoming transfer costs, but hey, at least it's a coherent identity. A number of homegrown players -- Auston Trusty, Matt Real, Anthony Fontana, Derrick Jones -- have already gotten minutes during the opening month of this season.

"We are not going to bring in a $10 million player," Union coach Jim Curtin told ESPN FC in a phone interview. "That's not in our DNA. ... On any given day, everybody has to play well for us to have a chance. In that way, we're kind of a true team. If we have an off night, we don't have any single guy who's going to bail us out."

That all-for-one ethos has yielded dividends before. Philly reached the U.S. Open Cup final in 2014 and 2015. In one-off tournament games, it seems, the gritty style Curtin prizes can make a difference.

Whether that holds up over the course of the marathon regular season -- and whether either his side or San Jose's can break into a hierarchy well established even in a salary-capped league -- remains open to interpretation.

"The margin of error for us, and for the San Joses of the world, is just a little bit smaller than it is for everybody else," Curtin said. "That's just the way it is."

That margin might only get thinner from here.