The Spurs originally signed the former BYU star on July 22. Fredette has played a total of 26 minutes this preseason and scored just four points.
Fredette, 26, has struggled during his NBA career, averaging 13.7 minutes and 6.1 points in six seasons. He averaged 3.6 points in 50 games with the New Orleans Hornets last season.
Fredette was taken with the No. 10 pick in the 2011 NBA draft by the Milwaukee Bucks after being named the Naismith College Player of the Year. Fredette played in 139 games over four seasons at BYU, scoring 2,599 points. He averaged 28.9 points and 4.3 assists his senior season.