The Rangers claimed Butto (arm) off waivers from the Giants on Monday.
Butto missed nearly all of this past season while recovering from two surgeries to address a blood clot and artery in his right arm. It's unclear where the right-handed reliever is at in his rehab. Butto holds a career 3.76 ERA and 185:99 K:BB over 189 innings at the big-league level.