The point guard, who tore his anterior cruciate ligament in January, is yet to be cleared for contact in practice.
Head coach Brad Stevens told the team's website: "He went through the morning workout and then he took the afternoon off. So he's probably going to do one workout a day.
"He's doing shooting drills, he's moving. We're not doing anything defensively [in the morning sessions], so there's not a lot of lateral movement there. But he's doing everything else.
"He was very active in the afternoon. He was in the huddles, he was in the drills as far as communicating. You saw him leading our stretching at the end."
Rondo average 13.7 points per game last season.