The Wizards announced Friday that Webster had surgery to repair a herniated disc in his lower back. The operation was performed Thursday in Los Angeles.
The team said Webster is expected to be sidelined approximately three to five months before resuming basketball activity. The optimistic end of that range would have him returning around the start of training camp.
The Wizards said Webster was injured during a routine workout at the team's practice facility last week.
Webster signed a four-year contract with the Wizards last summer. He averaged 9.7 points and 2.8 rebounds last season.