The phrase "bit player" refers to someone who has a small or unimportant role in a particular situation or event. They are not seen as a main character or significant participant. Full definition
Stock options were once bit players in the drama of capitalism, first intended back in the 1940s and 1950s as bonuses for key executives who could truly influence a company's fortunes. (inc.com)
What they soon discover is that they are mere bit players in a human trafficking scam. (moviereviewsfromthedark.com)
All you have to do is look at the graphs to see CO2 back radiation is a minor bit player when talking about the ocean. (wattsupwiththat.com)