The second-year forward was scheduled to undergo more tests. Parker had an MRI on Monday morning to follow up on discomfort in the foot.
The Bucks said the sprain was in the middle of the right foot.
Parker returned to the Bucks on Nov. 4 after missing the first four games of this season and the last 57 of the previous season with a torn left ACL. He was averaging 7.2 points and 3.6 rebounds in five games this year.
Parker was coming off season highs of 12 points and 30 minutes in a double-overtime win Saturday over Cleveland.