The Phillies optioned Sanchez to their minor-league camp Tuesday, Scott Lauber of The Philadelphia Inquirer reports.
The 24-year-old lefty has made only one career appearance above the High-A level, so he wasn't a legitimate candidate to claim a spot on the Phillies' Opening Day roster. Sanchez is expected to begin the season as a member of the rotation at Triple-A Lehigh Valley or Double-A Reading.