Stephen Belber, who’s written for television (“Law and Order” and “Rescue Me”) and films as well as the New York stage, is making his screen directorial debut with “Management,” a romantic comedy starring Jennifer Aniston and Steve Zahn that he scripted himself. But as he explained in a Dallas interview connected with the movie’s appearance in the USA Film Festival, the picture began on the boards.

“I was asked by a theatre company—it was this theatre company called Harvard 529, and it was named after the apartment where Joseph Chaykin lived in New York City—as part of a fund-raiser to write a play for two characters,” he said. “They asked seven or eight playwrights, including Sam Shepard—Chaykin directed a lot of early Shepard—to write plays that took place in motel rooms. So that’s what compelled me to make this little ten-minute play, and I found characters that I liked. It was a ten-minute play about six or seven years ago. I would come home and I knew that I liked these characters when I saw it performed. And a couple years later I decided to stick with them and see what would happen if they met after that. I would just write potential scenes of their further interaction. And then eventually I got around to writing the whole thing.

“I thought it would be fun, something I could really control, and if I ever wanted to direct something, it’s something very easy to direct, a character piece, something I wouldn’t mind putting my signature on.

“Even as a playwright, you yearn for more control of the actors. You eventually have to give the play to the actors in a play in theatre. In movies you can micromanage to the last minute, if you’re a control freak.

“This one I did want to try. At the same time I had written a much larger studio movie, but I knew I had no place in trying to pretend I could direct that.”

The casting proved easier than one might expect of a small film with a limited budget and a first-time director. “It was nice because for whatever reason, the script was sent out and got sent to various agencies,” Belber said, “and because it was a character piece, actors’ agents are looking for that. So it went around to various agencies, to the point where when I had a producer I could go immediately to those agents, and they were throwing all sorts of names around—most of it B.S.—and at one point Jennifer Aniston’s agent turned to me and say, ‘Well, I think it’s great for her, but I can’t give it to her without a straight offer.’ And I had always thought I would cast the male lead first, because it was a little bit more of his movie. So I was very flattered, but I wasn’t sure.

“And then a couple weeks later, he called and said he had already given it to her, without asking, and she liked it and wanted to meet. But if you wanted to meet with her it had to be an exclusive offer. And I wasn’t a hundred percent sure, but I went and rewatched some of her movies, and met with her and she was lovely and smart and thoughtful about the character and thoughtful about the entire piece. And that was great because it set up the financing in a way that allowed me more flexibility with the male role, because I knew I didn’t want a classic leading man. I wanted someone a little off. And she knew Steve from before and knew his work, and the idea worked.”

And Zahn, Belber felt, was able to maintain a difficult balancing act in his role. “I don’t know if I pulled it off,” he said, “but if I did it’s because of Steve Zahn’s ability to be harmless and charming and lovely even as he does these bizarre and potentially threatening things….I knew that if I could find an actor who could convey that sense of heart-on-a-sleeve and genuineness, I would ultimately be okay. A lot of actors could not have pulled that off. But it was tricky.”

Aniston and Zahn don’t work alone, of course, and “Management” boasts a strong supporting cast. Aniston’s ex-boyfriend is played by Woody Harrelson who was, Belber said, “very wild…and he was on the tail end of an all-liquid diet,” which made a dinner scene difficult, “because I was told he’s not going to eat. But we all went out to dinner that night, and he started to loosen up. I think he had a little crush on Jennifer,” he added.

Zahn’s parents are played by Fred Ward and Margo Martindale. “Margo’s been on a thing I’d worked on, ‘The Laramie Project,’” Belber said. “So I knew her work. Her name came up, and I said great. I wanted someone who had a soul, and I knew she did. Fred Ward—I was shocked that his name came up and he was willing. He actually came in and auditioned. I wanted that father-son story to have weight…I wanted a real damaged person, and Fred can do that. And James Liao, who garners laughs as a waiter in a Chinese restaurant who becomes Zahn’s best friend, was someone Belber had met at Juilliard years earlier and whose phone number he’d kept. “They wanted to interview every Asian actor from TV and movies, and I just stuck to my guns for James. He’s just so fun and weird—I love actors like that.”