The Yankees acquired De Los Santos and right-hander Thomas Balboni from the Padres in exchange for outfielder Brandon Lockridge on Tuesday.
De Los Santos had a 4.46 ERA, 1.29 WHIP and 48:13 K:BB over 40.1 innings for the Padres this season, but he was expendable with the club adding major bullpen pieces at the deadline. The right-handed journeyman had a 3.18 ERA in 120 outings for the Guardians across the previous two seasons, and he's likely to work in middle relief for the Yankees.