Padres manager Andy Green said that Schumaker will primarily be helping out with the Minor League system.
"He's making his rounds in the organization, offering insight at different levels," Green said. "It's a nice way to keep him involved in the game, and I think everybody here has a profound respect for him.
"We're excited to have him around."
Schumaker had an 11-year Major League career, where he played for the Cardinals, Dodgers and Reds, hitting a combined .278 over 1,149 total games.
Carlos Collazo is a reporter for MLB.com based in San Diego. Follow him on Twitter @CarlosACollazo. This story was not subject to the approval of Major League Baseball or its clubs.