Doc Rivers is concerned about the swelling Rajon Rondo has experienced in his sprained ankle as he tries to work his way back.

"Rondo is day to day," Rivers told WEEI in Boston on Thursday. "I don't know if you'll see him tomorrow or not, but he's getting close. So far each time he's worked out there's been some swelling and that's a concern. We're going to take it slow. We're not going to push him back. We're just going to wait until he's ready to play."

Boston will face New Orleans on Friday night.

"It was a pretty severe sprain," president Danny Ainge said later Thursday. "Rajon is in a situation where he could play, but he's in pain still. He has pain on both sides of the ankle and we just don't want to get him back on to the court until he can play hard."

The Celtics are 4-2 in Rondo's absence.