Ellis had been listed as doubtful with a lower right leg injury. The veteran guard is averaging 19.1 points, 4.2 assists and a team high 1.92 steals. He needs 10 points to hit 13,000 for his career and 10 field goals to reach 5,000 in his career.
Backup guard Barea has a sprained left ankle. He had been listed as questionable.
The Mavericks (45-28) currently hold the No. 7 seed in the chase for the Western Conference playoffs. They still have a four-game lead over eighth-place Oklahoma City.
Paul George will again sit out for Indiana (31-41) with a broken right leg.