Orr was outrighted off the Phils' 40-man roster earlier this season after hitting .286 with 12 hits and five RBIs in 23 games, and manager Charlie Manuel said Orr will provide depth as a utility infielder.
"We thought we were going to need another infielder," Manuel said.
The 33-year-old left-handed hitter may likely be more support for Placido Polanco, who is no longer an everyday player in Philadelphia.
"He's not available," Manuel said regarding Polanco. "He can play if he had to, in an emergency."
Polanco, 36, has struggled to stay healthy and was hitting .258 with two homers and 19 RBIs entering Tuesday.