Sonya Walger has joined the cast of Admission. The actress joins Tina Fey, Michael Sheen and Paul Rudd in the academia-based comedy. Walger will play “Helen,” a professor at Princeton, where the film is set. Paul Weitz is directing. Weitz and Kerry Kohansky are producing. Walger is a lead on USA Network’s recently debuted psychological police series Common Law. The actress is repped by Gersh and managed by Authentic’s Jon Rubinstein.