As odd couples go, football and Broadway make for one of the oddest.But that’s not stopping the NFL from going legit, signing on as a special producing partner for “Lombardi,” the pigskin-themed play that has nailed down a fall opening at the Main Stem’s Circle in the Square. Sports-centric Broadway offerings aren’t exactly common on the Rialto. One of the more recent examples was 2002 play “Take Me Out” — although it’s not clear that show, about the aftermath of a baseball star coming out of the closet, reached much beyond traditional playgoers to pull in baseball fans. On the other hand, “Lombardi” — a bio-play about Vince Lombardi, the legendary coach after whom the Super Bowl trophy is named — will target sports auds through the NFL, which will help promote and market the play. Org also has authorized the production to use its logos as well as footage and music from NFL Films. It’s an unusual partnership for the Rialto, and could attract major crowds to the show if it manages to attract even a fraction of the football lovers around the country. Project reps another example of legiters’ increasingly frequent efforts to tap demos that aren’t traditionally considered theatergoers. Tony Ponturo, topper of an eponymous sports and entertainment management company, and Fran Kirmser produce the play after working together on the current revival of “Hair.” Thomas Kail (“In the Heights”) will helm a six-thesp cast, to be toplined by Dan Lauria (“The Wonder Years”) in the title role. Play, based on David Maraniss’ Lombardi bio “When Pride Still Mattered: A Life of Vince Lombardi,” is penned by Eric Simonson, the Steppenwolf Theater Company member who also has written a previous play about the coach, as well as a stage adaptation of baseball story “Bang the Drum Slowly.” Lombardi is best known for resuscitating the Green Bay Packers when he became head coach of the team in 1959, leading the Packers to five N.F.L. championships over eight years. “Lombardi” will have a brief engagement July 22-28 at the Mahaiwe Performing Arts Center in Great Barrington, Mass., ahead of a Broadway run that beings previews Sept. 23 and opens Oct. 21 at Circle in the Square.