On June 28, 2007, Sessions was selected by the Milwaukee Bucks with the 56th overall pick in the 2007 NBA draft. On November 8, 2007, he was assigned to the Tulsa 66ers of the NBA Development League. He earned two D-League Performer of the Week recognitions before being recalled by the Bucks on February 1, 2008. He missed games from February 2–23 due to a left hand fracture. He made his NBA debut on March 9, 2008, recording two points, two assists and one steal in just over four minutes off the bench in a 119–97 loss to the Philadelphia 76ers.