Contreras signed a minor-league contract with the Phillies, Matt Eddy of Baseball America reports.
The Padres reassigned Contreras to minor-league camp Friday.
Contreras re-signed Wednesday with the Padres on a minor-league contract with an invitation to major-league spring training.
Contreras (arm) has struck out six over five shutout innings in his two outings since returning to action Aug. 4 for High-A Fort Wayne.
Contreras left Wednesday's contest for High-A Fort Wayne with a potential right arm injury, Justin Prince of WFFT Fox 55 Fort Wayne reports.
Contreras tossed one inning for High-A Fort Wayne on Friday, allowing one run on three walks while striking out one. It was his first appearance since he underwent Tommy John surgery late in 2020.