Beaubois appeared to come down on an opponent's foot in the third quarter of the win in Germany, according to WFAA in Dallas, and the severity of the ankle sprain is not yet known.
The fourth-year pro was making strides this offseason after showing flashes of brilliance last year for the Mavericks.
Beaubois scored four points and had an assist in 11 minutes against Alba Berlin. He teamed with Delonte West in the backcourt for Rick Carlisle's second unit, one more familiar with the team than the starting backcourt of O.J. Mayo and Darren Collison, who were both signed in the offseason.
Last season, Beaubois averaged 8.9 points, 2.9 assists and 2.8 rebounds per game. He played in 53 games of the lockout-shortened schedule.