"On the position player side, we've been thin and some guys definitely need to get off their feet," manager Mike Scioscia said. "The outfield depth is something we need for this weekend."
Salas was simply the victim of a "numbers issue," Scioscia said, as the Angels moved to a seven-man bullpen.
Since returning from the DL on July 6, Salas had a 3.86 ERA in six appearances.
"This move is totally a reaction to some of our outfielders being banged up and needing some depth and really has nothing to do with how Fernando was pitching," Scioscia said.
Shuck played in 19 games with the Angels in April and May, hitting just .173. After a three-hit game against the Mets on April 13, Shuck went 9-for-67 (.134) in his next 16 games.
"When I came up here the first time, I was just trying to do too much, and once I got in a hole, it just snowballed and got worse," Shuck said.
In 74 games at Triple-A Salt Lake, Shuck hit .318 with 42 RBIs.
Matthew DeFranks is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.