The Giants recalled Walker from Triple-A Sacramento on Friday, Shayna Rubin of the San Francisco Chronicle reports.
Walker began the season as the Giants' de facto closer but was demoted to Sacramento just over a month ago after posting a 6.46 ERA and 14:10 K:BB over 15.1 innings. He seemed to get back on track at Sacramento, permitting two runs with a 7:3 K:BB across 9.1 frames. No one has taken hold of the Giants' closer job since Walker was optioned, so he could push his way back into the late-inning mix. Initially, however, the club is likely to ease him in with some low-leverage outings.