EXCLUSIVE: Actors are being cast in Los Angeles for a non-union NBA TV commercial. A notice posted by Frontier Casting says the four-day shoot set for later this month is looking for actors of all ethnicities to portray “passionate” basketball fans. According to the casting notice, its union status is “non-union.”

The National Basketball League is not signed to the union’s contract, according to the SAG-AFTRA signatory page, so it’s not violating any union agreements. But SAG-AFTRA cautions that if union actors take the roles, they could face expulsion from the guild.

“SAG-AFTRA is cracking down on members who don’t honor the commitment they made to their union sisters and brothers to only work union,” the union’s website states.

The union says that over the past year, more than 130 members “have been caught and sent through the disciplinary process” where a committee of their peers can fine, suspend or expel them from the union.

Actors selected for the roles as NBA fans will be paid a $2500 buyout fee plus 10% for four days of filming, from August 21-24. Asked where the ad will be shooting and who the ad agency is, a Frontier official told Deadline, “We don’t give out that information.”

The buyout covers “All broadcast media including Internet, streaming, wireless streaming and social media, industrial, theatrical, radio and corporate.” No residuals will be paid no matter how often the ad runs anywhere in the world.

The guild launched a Commercials Organizing and Recapture Initiative in 2015 to stem the tide of nonunion commercial productions, which eat into the $1 billion its members earn each year on union shoots.

Actors submitting for the roles of NBA fans, the casting notice states, should have “strong improve and acting chops.” This fits the union’s research that’s found that “advertisers and ad agencies pursue improv performers and at times have been known to encourage them to work non-union commercials.” Last year, the union reached out to the improv communities in Los Angeles, New York and Chicago to alert them to “the disadvantages of working nonunion.”

Meanwhile, in its ongoing efforts to curb nonunion commercial production, SAG-AFTRA posted a statement on its website today that says that the Bartle Bogle Hegarty ad agency, which is a longtime signatory to the guild’s commercials contract, “is now disputing its status as a signatory.” The union says it’s challenging that position.

“We have not yet called for a strike against BBH. However, if we are unable to resolve this matter, we will take that step very soon,” the union told its members. “BBH believes it is free to disregard the terms of your contract, including contributions to your pension & health benefits, minimum compensation, and the responsible use of your image, voice and performance.”