Humphries sliced his right pinkie on a rim while attempting to block a layup in the Wizards’ 85-81 win against the Bulls Monday. The laceration prompted the surgery and required eight stitches.
Washington initially ruled him out for two games. The 29-year-old will most likely miss the season opener in Miami on Oct. 29 as he recovers.
The Wizards acquired Humphries in July as part of a sign-and-trade deal with the Boston Celtics. He averaged 8.4 points and 5.9 rebounds in one season with the Celtics.
The Wizards finished last season with a record of 44-38 before losing to the Pacers in the Eastern Conference Semifinals.