Black signed a minor league contract with the Giants on Friday, Rich MacLeod of MLB.com reports.
Black hasn't pitched in the majors since 2014 and is coming off shoulder surgery, but Giants scouts saw him throwing 97 MPH in workouts and decided their former reliever was worth a flyer. The Giants bullpen has been ineffective thus far (4.89 ERA), and anybody who brings that kind of heat is enticing for a club in that situation.