City's starting line up included Martyn Margetson, Gavin Gordon, Andrew Jordan and Des Hamilton.
Hamilton came through the 90 mins, his first action since going off injured against Bristol City before Christmas.
Match report from Plymouth Argyle.
Plymouth: McCormick, Connolly, Malcolm, Aljofree, Jeannin, Beresford, Bernard, Broad, McGlinchey, Keith, Lowndes.
Cardiff: Margetson, Williams, Jordan, Collins, Jones, Zhiyi, Hamilton, Dimond, Naglieri, Maxwell, Gordon.
