sixth man
Noun
Meaning
(basketball) A player who is not a starter but comes off the bench much more often than other reserves.
By extension, a person or group who is not part of a team, but who supports or contributes to the success of the team.
Source: en.wiktionary.orgExamples
Finally, under which of the old tyrannical governments of Europe is every sixth man a slave, whom his fellow-creatures may buy and sell and torture?
Harrell has been a key member of the Clippers' bench this season and is a contender for the NBA's Sixth Man of the Year Award.
Last week, the Clippers’ reserve center Montrezl Harrell was awarded the Sixth Man of the Year award for the first time, marking the fifth time in seven seasons a Clipper has won that award.
Teammate Karson Parker was named as the Sixth Man of the Year.