The NFL has worked in recent years to take some commercials out of America’s favorite game. The XFL is experimenting with new ways to push them in.

Anyone who watched the new league’s St. Louis BattleHawks triumph over the Dallas Renegades in its first week of official play might have noticed ads for Bud Light Seltzer affixed to the helmets of the Texas home team. It’s a placement two more established sports leagues – the National Football League and Major League Baseball – have avoided, at least up until this point.

At the XFL, however, “I think you’re going to see more as the season progresses,” says Jordan Schlachter, chief marketing and commercial officer of the XFL, in an interview. The league has tried other marketing maneuvers as well: Followers of the St. Louis team might have imbibed even more images of the new hard seltzer, which was featured in videos of a BattleHawks locker-room celebration sent out over social media (XFL executives say the beverages were placed there deliberately and interaction with them by the players not mandated). Fox and ESPN have rights to broadcast XFL games.

By putting ads on uniforms, the XFL Is crossing a line that still needs to be traversed delicately. Sports fans can sometimes balk at seeing commercials squeezed onto uniforms or the field of play, as they did in 2004, when Major League Baseball and Sony Corp. struck an agreement to put web designs on bases as part of a promotion for the movie “Spider-Man 2.” More than a decade later, Madison Avenue is eager to push right through the border: The National Hockey League embeds ads in the ice and the National Basketball Association, has, after a trial period, allowed teams to sell “jersey patches” to sponsors.

“The XFL’s willingness to put Bud Light Seltzer logos on the backs of helmets doesn’t surprise me in the least. It’s consistent with the league’s receptiveness and openness to be innovative and different,” says Patrick Rishe, director of the sports business program at Washington University in St. Louis. “Don’t be surprised if the NFL adopts a similar strategy within three years.” The NFL declined to comment.

Executives at Anheuser-Busch InBev, the maker of the new Bud Light Seltzer, are eager to see if they can gain ground for their technique. “I think the XFL being a new league, they are a little more lenient in terms of things they can offer to sponsors, so we saw this as an opportunity to market our products in new and unique ways,” says Nick Kelly, vice president of partnerships, beer culture and community at Anheuser-Busch InBev, in response to questions via email. “We’re going to continue doing that as the rest of the season unfolds and take the learnings with XFL and translate them to more traditional sports.”

With younger viewers growing accustomed to streaming video favorites with fewer ads – and, in some cases, none – big sports leagues have in recent years pared down some of the interruptions in broadcasts of their games by Fox, NBC, CBS, ESPN and others. The NFL and Fox this year took a commercial break out of each quarter of the broadcast of Super Bowl LIV, following a few seasons of the NFL removing some commercial breaks from regular season game play. Just this past weekend, the NBA elected to air the final quarter of its annual All-Star Game without commercials, part of an effort to honor Kobe Bryant after his tragic and unexpected death.

But big advertisers still want to find other ways into the games.

They have good reason. Sports broadcasts are one of the few traditional TV properties that can still capture a large, live audience that is willing to watch the ads that interrupt the event. And the networks are often more lenient about mixing commercials with content in sports broadcasts than they are with scripted comedies or dramas. Sports matches regularly feature sponsored graphics, shout-outs to key advertisers in the midst of game play and “billboards,” those seconds-long nods to whichever automaker, brewer or insurance provider is pouring ad money behind the scenes.

A start-up like the XFL probably has the leeway to test unorthodox methods. “Emerging and secondary leagues often serve as marketing laboratories, as less controversy tends to follow their revenue producing efforts,” says David Carter, a professor of sports business at USC’s Marshall School of Business. “They serve as a fan- and brand-oriented, real time focus group whereby trial balloons can be launched. If or when any dissent is raised and addressed, these changes make take permanent hold with more established leagues.”

The NBA likes what it has seen from use of the patches on team uniforms. The league set up a three-year pilot program to test the ads from the likes of FedEx and Western Union just before the 2017-18 season, says Matt Wolf, senior vice president of team marketing and business operations at the NBA, in an interview. But by the second season of the program, the concept was made part of the rules. All 30 teams now utilize patches. The NBA early on focused on “trying to ensure the patch was viable for the partner but didn’t distract from the jerseys themselves or our very powerful, very valuable team brands,” says Wolf.

The patches are just two and half inches by two and a half inches, but even that amount of space has generated an estimated $150 million in new revenue for NBA teams, according to Navigate Research, a Chicago consultant that analyzes sports and entertainment sponsorships. The NBA declined to comment on revenue from the jersey program.

The only people who can really call a flag on the new advertising plays are people who pay to watch their teams in action. “We are going to be listening all the time to what our fans have to say across social media and to our teams,” says Jeffrey Pollack, the XFL’s president and chief operating officer. The league also maintains an online panel of fans that it can utilize to examine sentiment on everything from the live game experience to advertising. At the same time, he says, the XFL needs to stand apart from others to thrive. “We know that we have to prove ourselves to be a meaningful and differentiated platform to the leading brands in sports marketing and to brands that maybe haven’t been in sports marketing before.”

If the XFL thrives with this technique, more ads may make their way to uniforms and playing surfaces in some of the nation’s most-watched games – circumventing the TV networks that show the games. As with most popular sports, proof of success will be found on the field.