Wittman did not give a reason for Nene's absence. The Brazilian native twisted his right ankle in a victory over Brooklyn on Friday but played 27 minutes in Sunday's victory over Atlanta.
The Wizards (46-34) have already locked up the No. 5 seed in the Eastern Conference playoffs and have posted their highest win total since 1978-79 when they had 54 victories.
But Nene's absence could have an impact on the final playoff spot in the East. With two games left, Indiana (37-43) currently has a one-half game lead over Brooklyn for the No. 8 seed.
Indiana will make the postseason with two wins or a win and a Brooklyn loss.