sideline nigga 

A dude that take the place of a starter when he ain't doing his job. Aka Chris Byrd

Girl 1 : Girl what's wrong?
Girl 2 : My man ain't shit
Girl 1 : Call your sideline nigga from off the bench

sideline nigga by Thotty McSidelined December 6, 2013

Sideline Nigga 

A nigga that stands on the sideline and doesn’t do shit.

Shut up you a sideline nigga

Sideline Nigga by Abe El Babe September 6, 2019