ride the pine
In sports (especially baseball), to remain sitting on the bench, rather than be an active participant in the game. Primarily heard in US. I'm not going to play next year if coach makes me ride the pine again this season. I rode the pine for the rest of the game after I pulled my hamstring sliding to first base.
ride the pine (or bench)
(of an athlete) not participate in a game or event, typically because of poor form. North American informal