The Giants recalled Suarez from Triple-A Sacramento ahead of Monday's series opener against the Cardinals.
Suarez previously made two starts with the big club earlier this season and 29 in 2018, but he's expected to fill a long-relief role in September with youngsters Tyler Beede, Logan Webb and Dereck Rodriguez currently occupying the final three spots in the rotation and Johnny Cueto (elbow) expected back from the injured list next weekend. Even against lower-caliber competition in the Pacific Coast League this season, Suarez failed to find much success, submitting a 5.73 ERA and 1.64 WHIP in 88 innings.