"I think he's been swinging the bat pain free, even with the vibration," manager Bryan Price said.
Phillips, who was expected to miss six weeks after his operation, is expected to go on a Minor League rehab assignment before rejoining the Reds.
"There will be some Minor League season left for Brandon to go on a rehab assignment and hit," Price said.
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. This story was not subject to the approval of Major League Baseball or its clubs.