What if we built smaller NFL football stadiums?

Hard to imagine, yes — especially in this era of ever-growing sports complexes (see: Rams owner Stan Kroenke's blueprint for a mini-city in Los Angeles, including a stadium of 90,000-plus capacity). But for the architects and industry insiders looking, say, 25 years into the future, that idea isn't so far-fetched.

A number of innovations could conspire to make smaller footprints a reality. One is modular technology, possibly helped by advances in ultra-lightweight carbon fiber and other materials, that would allow stadiums to transform for different kinds of events. This isn't about turning a basketball arena into a concert venue by plunking a stage on the floor. Rather, picture an entire section of seats smoothly sliding up and backward into a new position — revealing more seats underneath — so that that same basketball arena becomes friendly for soccer. Such a venue already exists in Japan, where the Saitama Super Arena boasts a movable section of seats that can increase its capacity from roughly 20,000 to more than 35,000.

"I definitely think something like that could become a factor in a place like New York where there isn't a lot of land and you do have a demand for both types of venues," architect Dan Meis, who designed the Saitama Super Arena, told Sports Illustrated and Wired as part of a series that examined the future of football. His company MEIS Architect also designed two current NFL stadiums, Paul Brown Stadium in Cincinnati and Lincoln Financial Field in Philadelphia.

Another key is driverless technology. With self-driving cars shuttling fans to and from the game, there'd be no need for sprawling parking lots adjacent to stadiums. Twenty to 30 percent of that space could be annexed by the stadium complex and used to create an inside-the-gates tailgating experience — and still the overall footprint would be smaller than today.

"The Future of Sports" — a recent report spearheaded by Boston Bruins owner Jeremy Jacobs that envisions all aspects of the industry's future — signs onto this idea. The result, it says, will be "open-concept venues" not unlike today's baseball parks. Fans who want them can still have their luxury boxes, but others could wander the complex, watching the game on massive high-definition jumbotrons from standing bar areas and picnic tables. (Speaking of jumbotrons, video walls built into stadium architecture will be bigger and more vivid; other visual technology that could come online include hologram projections of the game and of replays, and personal video feeds that allow users to follow their favorite players.)

Scott Radecic, senior principal and architect for the Kansas City-based sports architecture firm Populous, conjures a similar scene. Speaking as part of the same Sports Illustrated-Wired series, he described an urban stadium where the lower bowl is sunk into the ground, with seating for 30,000 die-hard fans who want to stay close to the action. The upper bowl, however, would not be the tiered nose-bleeds of today. Rather, it would appeal to the fans who want a social sports experience that allows them to move around. Picture a mix of open walkways and city bars with back-patio or rooftop areas that allow views onto the game. Fans could rent camera-equipped drones and create personalized live-game feeds. Or gather in "neighborhoods" that have different personalities.

"The variety of experiences will prove limitless, and they'll be dictated heavily by the local culture," wrote Sports Illustrated's Tim Newcomb. "This focus on social gatherings will allow people to grow more connected with each other over the sport they love."

Radecic also emphasized the need for stadiums to be multi-use and integrated with their surrounding city. Remember that sunken lower bowl? Imagine an adjacent office building that, on NFL Sundays, turns its field-facing offices into luxury suites. The area outside the upper bowl could act as a park for dog walkers and stroller-pushers. "We think about these stadiums every day — how they're changing, how our fans are changing," said Radecic.

Signs of this longer-term evolution can already be seen in today's NFL. That Rams' plan, for example, calls for a multi-use complex that includes a hotel, housing, retail, and office space, and more. The stadium will be set into the ground with an above-ground profile of only 175 feet. It will have open stands and concourses. And one of its main attractions will be "Oculus," a 50-foot-tall, 120-yard ribbon-like video board that encircles the field.

But with all of this happening on a 300-acre site that's nearly three times the size of Vatican City, it's clear that bigger continues to better. For now.