The Grizzlies announced Sunday that Anderson had a Grade 2 sprain. Anderson hurt the ankle Saturday in a 112-108 loss at Miami.
Anderson has made 38 starts in his first season with the Grizzlies. He is averaging 7.9 points, 5.8 rebounds, 3.0 assists and 29.7 minutes.
The 6-foot-9 Anderson received a four-year, $37.2 million deal with the Grizzlies as a restricted free agent last summer after spending his first four seasons with the San Antonio Spurs.