Rondo was seen limping off the floor Monday at the team's practice facility.
"He just twisted his ankle, nothing bad, but instead of keeping him out on the floor, easier to take him off," Rivers said.
Rondo has sprained his right ankle twice previously this season but has only missed two games.
Rivers said he did not know which ankle Rondo injured. Rondo has sprained his right ankle twice previously this season but has only missed two games.
Meanwhile, Rivers said Kevin Garnett was making improvement as he rehabs his sprained right knee.
"I'm just really happy with what we see," Rivers said. "A week ago there was more concern. This week, less concern. He looks great, he's moving great. You can just tell the difference."
Rivers said he expected Garnett to accompany the team during the final road trip of the regular season to Cleveland and Philadelphia. He ruled out Garnett playing against the Cavaliers on Sunday, but said he could play April 14 against the 76ers.
"He won't play this week, Wednesday, Friday or Sunday. But he's going to go on the road with us and start practicing," Rivers said.
"Actually, our hope is to start practicing our entire team on this little road trip, which would be really nice since I haven't seen them in a while, and I think it's possible," Rivers said.
Monday was the team's first practice since beating Atlanta at home on Friday night as Rivers gave the team the weekend off.