Moscoso formerly pitched for the Oakland Athletics in 2011, and was 8-10 with a 3.39 ERA in 21 starts. He was traded to the Colorado Rockies before the 2012 season, and he was 3-2 with a 6.12 ERA in three starts.
The 29-year-old has spent all of this season with the Cubs’ Triple-A affiliate, where he is 7-5 with a 3.93 ERA in 17 starts.
Henry Schulman of the San Francisco Chronicle reports that Moscoso will be with the Giants on Saturday, as the team looks to add to their pitching depth.
The Giants have also activated infielder Joaquin Arias off the disabled list after he underwent an emergency appendectomy two weeks ago.
Arias is hitting .282 with 10 RBI this season in 60 games, and has been one of their most consistent bench players, offensively and defensively.
To make room for Arias, the team sent down relief pitcher Jake Dunning to Triple-A Fresno. Dunning, a rookie, appeared in 20 games for the Giants and recorded a 2.84 ERA and an 0-1 record.
The Giants are still without leadoff hitter Angel Pagan (hamstring), starting pitcher Ryan Vogelsong (hand), and relief pitcher Jeremy Affeldt (groin).