Citi Field will host its first postseason baseball game Monday night. It's been more than six years since the stadium opened its doors -- and nine years since the New York Mets last made the playoffs.

Mets fans know it feels like a long time.

But across the street, a game with far larger implications has gone on far longer, and there's no end in sight. It's a game the region mustn't lose.

Anyone who's been to Citi Field, or traveled on the 7 train as it passes by, knows about the Iron Triangle, as the area next to the ballpark is called. They know about the unpaved roads, sewerless land, and shrinking number of industrial businesses, from waste management to auto repair.

But the swath called Willets Point is also home to 62 acres of possibility, from affordable housing to new commercial development. It's in a site critical to NYC, where baseball meets tennis, where the subway meets the LIRR, and where both might link to an AirTrain to LaGuardia Airport.

A new Willets Point has been more than a decade in the making and has hit more potholes than scar the area's streets. NYC must keep its redevelopment at the top of its agenda.

Michael Bloomberg made Willets Point a priority throughout his mayoralty. Eventually, a request to developers for proposals in 2011 led to several applications, including the winning one from a partnership between Related Companies and Sterling Equities, which owns the Mets.

As initially conceived, the Willets Point project would include a 1-million-square-foot mall, with movie theaters and parking facilities, on the Citi Field parking lot. Across the street, just beyond the outfield walls, the Queens Development Group would build 30,000 square feet of retail space and a 200-room hotel along 126th Street. On 23 acres of the Iron Triangle, beyond Citi Field's Pepsi Porch, they'd construct 2,500 housing units, including 875 affordable units, as well as a school, open space, and more office and retail.

Here's the problem. The Appellate Division of the State Supreme Court this summer nixed the mall, saying the parking lot is parkland and off limits for retail development, unless the State Legislature were to specifically authorize it.

The developers argue that the state allowed for development on the land when it allowed construction of Shea Stadium in the 1960s. They say the state's permission then would allow a mall now. But mall opponents say the stadium is the only construction allowed. We'd like to note that Shea Stadium -- the originally approved use for the land -- was located on the current Citi Field parking lot.

That seems complicated enough, but making the revival of Willets Point even tougher, city officials chose not to join the appeal of the court decision, leaving the developers on their own. Now no one's sure what'll happen next.

Mayor Bill de Blasio seems hesitant to carry the Bloomberg mantle on this, and that's unfortunate.

De Blasio staffers say they want tighter deadlines and would like to see additional affordable housing built on a faster timetable. So, now should be the time to work with Sterling and Related to craft a solution that makes sense. Instead, the city chose to separate itself, hoping it'll ultimately get a better deal from the developers. And city officials seem unfazed by the possibility that the agreement could fall apart, and they could be forced to start over.

If the state Court of Appeals rules in favor of the mall, then it's likely the project will move forward, potentially with different terms and timetables. But if the court refuses to hear the case, or says the Citi Field parking lot is protected parkland, the mall likely would be off the table. And the project may not be economically viable without it. Then, it'll be time to get creative.

The city has spent $400 million of taxpayer money to buy the land and on other project costs. The developers have been involved for nearly four years. Starting over would be a leap backward. The city is right to negotiate for clearer, tighter timetables and additional affordable housing. The development group seems amenable to both. But the city's decision to draw political battle lines may have huge ramifications. De Blasio must be realistic about what will work for all involved.

No matter how the mall's future shakes out in court, the city and current developers must craft final terms that make sense and get construction started. They must balance revenue-generating retail and commercial construction with the critical affordable-housing component. They must set and meet timely deadlines so the land no longer lingers as an untouched eyesore. And they must involve the community.

That's a lot to demand, but it's what they signed up for long ago. Then there can be many winners at Willets Point.