HBO’s pilot based on the Showtime Lakers of the 1980s continues to build out its cast.

Variety has learned that Gaby Hoffmann has been cast as Claire Rothman, while Hadley Robinson has been cast as Jeanie Buss. Rothman is the general manager of the Forum — the first and only female manager of any major market sports arena. The character is said to use her searing intelligence and emotional endurance to thrive in the misogynistic world of professional sports. Buss is the daughter of Lakers owner Jerry Buss (played in the pilot by John C. Reilly). Described as ambitious, smart and eager to prove herself as competent as the men around her, she weighs the competing influences of her role models to forge her own identity as a businesswoman.

In addition to Reilly, they join previously announced cast members Jason Clarke (Jerry West), Quincy Isaiah (Earvin “Magic” Johnson), Solomon Hughes (Kareem Abdul-Jabbar), DeVaughn Nixon (Norm Nixon), Joey Brooks (Lon Rosen), Molly Gordon (Linda Zafrani), Rob Morgan (Earvin Johnson Sr.), Spencer Garrett (Chick Hearn), Kirk Bovill (Donald Sterling), and Delante Desouza (Michael Cooper).

Hoffmann most recently starred in the Emmy-winning Amazon series “Transparent,” which recently ended after four seasons and a musical finale special. She previously appeared in the critically-acclaimed HBO series “Girls.” She earned three total Emmy nominations for her roles in both shows. Her other TV credits include “Louie,” “The Good Wife,” and “Private Practice.” As a child star, she appeared in films such as “Field of Dreams,” “Sleepless in Seattle,” and “The Man Without a Face.”

Robinson is a recent Julliard graduate who will make her feature debut in Greta Gerwig’s upcoming film adaptation of “Little Women.” She will also appear in the upcoming Charlie Kaufman film “I’m Thinking of Ending Things” and the Amazon series “Utopia.”

Both Hoffmann and Robinson are repped by UTA.

Max Borenstein is writing and executive producing the one-hour pilot. Adam McKay will direct the pilot and executive produce through his yet to be named new production company. Kevin Messick of McKay’s company will also executive produce along with Jason Shuman. Jim Hecht co-wrote the story and will also executive produce. Scott Stephens will also executive produce with Rodney Barnes co-executive producing. The pilot is based on Jeff Pearlman’s non-fiction book “Showtime: Magic, Kareem, Riley, and the Los Angeles Lakers Dynasty of the 1980s.”

(Pictured: Gaby Hoffmann, left; Hadley Robinson, right)