benchwarmer
/ˈbɛntʃˌwɔrmər/Definitions
1. noun
A player who spends most of a game or season on the bench, often without playing much or having a significant role.
“The team’s star player was initially a benchwarmer, but he eventually got more playing time and led the team to victory.”
2. noun
A person who provides moral or emotional support to others, often without being directly involved or recognized.
“She was a benchwarmer for her friend who was going through a tough breakup, offering a listening ear and words of encouragement.”