Peralta said the injury is affecting his command, and while he's not feeling any pain or soreness in his right arm, he had been having trouble finishing his pitches. In his last four appearances, starting with the series opener in Philadelphia on Aug. 4, Peralta has allowed five runs and three homers in 3 1/3 innings.
"When he starts talking about not being able to finish a pitch, that's when you get in trouble with guys," Dodgers manager Don Mattingly said. "I think we're seeing a little bit of that with his breaking ball."
This is the second time this season that Peralta has been placed on the disabled list with a neck issue, although he said that this injury isn't as bad as the one that forced him to miss nearly two months earlier this season.
"It's stuff that happens over the years, it's not something that happens overnight. I'm getting old, man," the 39-year-old Peralta said.
Garcia, 24, was a mainstay in the Dodgers' bullpen to start the season, but has spent much of the time since the All-Star break in Oklahoma City. Garcia has a 3.99 ERA in 41 appearances this season for the Dodgers.
Steve Bourbon is an associate reporter for MLB.com.