He landed guest appearances on dramas such as Boston Public, Gilmore Girls and The O.C. Greenfield scored his first lead role on the short-lived series Modern Men as one of three bachelors who hire a life coach to help them understand and manage women.
Dia mendarat menjalankan tugas tamu di drama seperti Boston Public, Gilmore Girls dan The OC Greenfield mencetak peran utama pertamanya di pendek-tinggal seri Modern Men sebagai salah satu dari tiga bujangan yang menyewa "Life Coach" untuk membantu mereka memahami dan mengelola perempuan.