While the footballing world fixes its eyes on Brazil, a much more local soccer rivalry will be officially inaugurated in New York on Saturday night, as the New York Cosmos host New York Red Bulls in the US Open Cup.

A year before the debut of the Yankees-backed New York City FC, it will be the first meeting between two professional New York soccer teams.

Given the Cup’s knockout format the game has been trailed, by the Cosmos especially, as a battle for New York – certainly for the type of bragging rights fans enjoy. But with NYCFC and their marquee signing, the Spain striker David Villa, beginning their march towards a notoriously competitive sporting market, the game also represents a rare chance for the now upstart Cosmos to gain more than symbolic territory.

To those whose American soccer knowledge extends to Pele’s appearances for the Cosmos in the 1970s, hearing them referred to as upstarts may seem strange. But that’s exactly what they are. The Cosmos dominated the North American Soccer League (NASL) in the 70s and 80s but folded with the league as TV and revenue interest dwindled. Their brand stayed alive, though not as much more than a trademark, before new owners and investment saw a return to competition in a similarly revived NASL.

Pele attended the opening game, the history of the team was repeatedly emphasised (just last week the team retired the No9 jersey worn by the late club and Lazio legend Giorgio Chinaglia) and the Cosmos did the business on the field – winning the fall season and then a sixth Soccer Bowl.

But the first five were won when the NASL was the top-tier US league. Now it’s the official second division, and the Red Bulls play in the first, Major League Soccer.

Pele in spectacular action for first incarnation of the New York Cosmos. Photograph: George Tiedemann/Time Life Pictures/Getty Images Photograph: George Tiedemann/Time Life Pictures/Getty Images

The NASL likes to tout its more open model than the forced parity/franchise structure of MLS, and has even been lobbying for a Concacaf Champions League place for its champions – as part of an attempt to fill the gaps left by MLS expansion and ultimately outflank the dominant league. But for even NASL's flagship team, the Cosmos, the path to sustainable success is a tough one.

Given the absence of promotion and relegation there are few realistic opportunities for the Cosmos to challenge the status quo, or indeed their de facto demotion to the Big Apple's third team when NYCFC enter MLS in spring 2015.

So Saturday’s game will be as important for the Cosmos as it will be a potential no-win for the Red Bulls, who can either beat a lower-league team as they’re supposed to or deal with the headache of defeat.

Red Bulls head coach Mike Petke, who like Cosmos coach Gio Saverese is a veteran of the New York soccer scene, has had to walk a fine line. He knows how the game will be seen locally and has a historic soft spot for the Open Cup (he did his case to succeed Hans Backe no harm when as an assistant he led the team in a road game to which the Swede did not travel).

Yet for the club's absentee Red Bull bosses in Austria, MLS success is all that counts. Recently, Petke said:

“If we were playing any other team in the NASL from a different state or something I wouldn’t be getting these same questions … I’m gonna make sure that my guys are up for it but obviously this is a huge, huge thing for the Cosmos and the NASL. It’s a huge thing for us only in the fact that we want to win a game and we want to advance in the competition.

On Saturday at Hofstra University on Long Island, Petke is likely to field a team without several starters – the likes of Thierry Henry and Jamison Olave rarely play on turf anyway, let alone in Open Cup games. A difficult start to the MLS season also means that the game is a now rare chance to give experience to fringe players.

They will be up against Cosmos starters. For Savarese, the Cosmos have “nothing to lose”. His captain, Carlos Mendes, a former Red Bulls defender, sees the game as “very special”.

The New York Red Bulls can usually employ Thierry Henry and Tim Cahill. Not this weekend. Photograph: Reuters Photograph: Jim McIsaac/Getty Images

Both have tried not to appear too obviously excited, but after the Cosmos beat the amateur Brooklyn Italians to set up this game, the coach could not resist comparing it to the recent Atlético Madrid-Real Madrid Champions League final.

He did so as a handful of reporters shivered on the touchline of a college soccer field in Queens – the modern Cosmos era is often a mix of the grandiose and the bathetic.

As is the case for many MLS teams now, the Open Cup was never a priority for them in their old, top-tier incarnation. But as David Villa and NYCFC may soon be telling both these teams, this is a different era in New York, and you have to land your punches when and where you can.