Francisco has played 81 games in the majors. The lefty hitter has a career batting average of .284 with five home runs and 29 RBIs.
Hoover was drafted by Atlanta in 2008. The Reds will assign him to Triple-A Louisville.
Hoover split last season between Triple-A and Double-A as a starter and reliever. The 24-year-old was a combined 3-6 with a 2.64 ERA.