"He's playing tomorrow. No questions about it," said Washington. "He told you my thoughts before I even thought it. Definitely tomorrow. Just giving it a rest."
Rios did not play in Friday's 4-3 loss to the Astros, but he was available to pinch-hit or come into the game if needed.
The ankle has been troubling Rios, who sprained the ankle on July 19 at Toronto. He missed three games from July 20-22 due to the injury.
Richard Dean is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.