An early MVP candidate, Antetokounmpo had missed just two other games this season. He is averaging 26.6 points, 12.8 rebounds and 6.0 assists per game.
Bucks coach Mike Budenholzer said Friday that Antetokounmpo was injured a couple of games ago.
In Milwaukee's previous game, a 116-109 win over the Rockets on Wednesday, Antetokounmpo tallied 27 points and 21 rebounds.
In Antetokounmpo's absence against Washington,Khris Middleton led the Bucks with 25 points and eight rebounds in a losing effort.
Giannis' 5 dunks, 30 points power Bucks past Jazz
Giannis Antetokounmpo shines, dropping 30 points for the Bucks in a 114-102 win over the Jazz.
Giannis dominates in Bucks' win
Giannis Antetokounmpo stuffs the stat sheet with 27 points and 21 rebounds in Milwaukee's convincing road win in Houston.