Longman Dictionary of Contemporary English
bit player
noun
EXAMPLES FROM CORPUS
▪ He drifted into films as a bit player in 1912 and went on to produce dozens of comedies.
▪ Now she was a bit player in my Orwellian nightmare.
▪ To visit Venice gives the sensation of viewing an ancient and famous movie, with each bit player a star name.
Wiktionary
bit player
n. 1 (context theater film English) An actor who has a minor role in a production. 2 (context figuratively English) An insignificant or unimportant person (in a particular situation).