"minor non-speaking role," 1902, theatrical slang. Meaning "actor who has such a part" is attested from 1946. The sports team sense is recorded from 1974.
(also step on) To interfere with a radio transmission by transmitting at the same time (1970s+ Citizens band radio)
: Since antiquity the figure of the black has played far more than a walk-on part in Western culture
A very minor, usually nonspeaking, role; an insignificant or minimal sort of participation: looking like last-minute walk-ons in the closing scene of ''Go¨tterdammerung'' (1900+ Theater)