The Thunder is filling its 15th and final roster spot with the signing of shooting guard Reggie Williams to a 10-day contract, The Oklahoman has learned.

The team is expected to announce the signing Thursday morning.

Williams, a 6-foot-6 sharpshooter with four years of NBA experience, is being called up from the Thunder-owned Tulsa 66ers of the NBA Development League. He is averaging a team-leading 21.1 points per game for the 66ers, along with 5.4 rebounds and 4.9 assists in 37.5 minutes. In 19 games this season, 15 as a starter, Williams has shot 49.5 percent from the field and 39.5 percent from behind the 3-point line. He is the D-League’s reigning Performer of the Week for his efforts in leading the 66ers to a 3-0 record while averaging 25.3 points, 7.8 rebounds and 4.3 assists and 2.3 steals.