Rivera has played in six games since coming to the Cubs and has done a serviceable job. Contreras returns after the rosters expand, so it makes sense that Rivera will stick around for the rest of the regular season. If the Cubs make the post season with Contreras healthy, Rivera will watching from home.
He is the 42nd player to suit up for the 2017 Cubs. Here they are in a nice 6 x 7 tile.