The star has not held a starring role in a TV series since "Dawson's Creek" ended in 2003.
Her last TV stint was a two-episode appearance on "How I Met Your Mother" in 2013.
The 35 year old will play the philanthropist wife of Rufus Sewell's character in the as-yet untitled series, which will film in New York later this year.
Speculation surrounding their intimate scenes has been rife for months, but now the British actress has revealed there was no penetration.
She tells Nylon magazine, "Neither Shia nor I were willing to actually have sex onscreen, obviously."
But Martin can understand why film fans believe they saw something they didn't, adding, "Everything was set in place for us to have a porn double, a prosthetic vagina, special effects.