The Giants recalled Smith from Triple-A Sacramento on Wednesday, reports Susan Slusser of the San Francisco Chronicle.
Smith will rejoin San Francisco after making just one appearance for the big-league club on May 10. In Triple-A, the 26-year-old has a 3.98 ERA, 1.23 WHIP and 23:10 K:BB. The right-hander will replace Matt Gage (knee) in the bullpen as he heads to the 15-day IL.