The Reds recalled Phillips from Triple-A Louisville on Friday.
The right-hander is joining the Reds ahead of Friday's game in St. Louis as Wade Miley (forearm) heads to the injured list. Chase Petty will be added to the MLB roster Saturday to start in place of Miley, so it could be a short stay in the majors for Phillips, who last appeared in the majors in 2023 and had a 6.97 ERA over 20.2 innings.