Smith (elbow) was reinstated from the disabled list prior to Wednesday's game against San Diego, Alex Pavlovic of NBC Sports Bay Area reports.
Smith appeared in six minor-league rehab outings over the past couple weeks and looks fully operational after undergoing Tommy John surgery in March of 2017. The left-hander figures to pitch in high-leverage spots within the Giants' bullpen after posting a 3.35 ERA and 1.21 WHIP over 40.1 innings of work split between San Francisco and Milwaukee in 2016. In a corresponding move, the club optioned Austin Slater to Triple-A.