The point guard was the team's top scorer during the 113-111 overtime loss, but he scored from just nine of his 29 shots from the field, and missed what could have been a game-winning shot late on.
The 23-year-old told reporters: "It starts with me. I took too many shots tonight and didn't move the ball like we're supposed to in the first half.
"For some reason, we don't go out there in that first half when we've got an opportunity to go [above] .500 and play as a team. We get to playing selfish."
The Wizards travel to the Phoenix Suns tomorrow.