In the 2013 NBA Draft, Porter was chosen third overall by the Washington Wizards. But he missed training camp and the first eighteen games of the 2013–14 season due to a hip injury.
In a 109-105 overtime loss to the Milwaukee Bucks on December 6, Otto made his NBA debut, going scoreless for 14 minutes.
In April 2014, he also had two nine-point games, which was a season-best. In a 114–99 loss to the Atlanta Hawks on November 7, 2015, he set a new career best with 23 points.
The American player scored 23 points for the second straight game as he defeated the New York Knicks 113–110, shooting six three-pointers along the way.
