Rivers said he has multiple game plans based on Allen's availability.
"Probably game-time," Rivers said of Allen, who has not played in two weeks with a sore right ankle. "The way I think it'll probably end up, he'll go over and do his routine early, and honestly, if you want to gauge it, if he gets through his routine, which he hasn't been able to do the last two times he's tried to play, then he'll probably play.
"That's how I'm going to judge it. My coaches will call me and let me know, but we've got two plans, one with him and one without. And one with him and maybe not in the second half, we just don't know. That's just the way we'll play it."
Allen took some shots while reporters were present before the start of the team's walk-through on the campus of Georgia Tech. He was cryptic on his status, stressing his desire to play, but suggesting he needed to be fully confident in the balky right ankle given the increased intensity of playoff basketball.
"I'm trying not to (think about the ankle), I'm just taking a day to go through it and understand how my body feels," said Allen. "It's kinda hard, it's the playoffs. I gotta be totally ready and, as much as I know I can help the team, I don't want to detract away from the team."
Allen said he'd make the decision about his status "soon." He was unable to go through practice on Saturday, noting the ankle simply wouldn't allow him to do as much as he would have liked.
If Allen does play, Rivers expects him to be typical Allen.
"If I play him, I expect him to make shots," said Rivers. "We're not going to put him on the floor unless we think he can play well. Obviously, he hasn't played, so his conditioning can't be very good. I don't know. (If he's able to play), we're just going to put him out there and see."
Allen admitted Saturday that he will require surgery at some point, but also said it is not an option now because of the playoffs. He said if this were the beginning of the season, he would opt to have surgery.
Rivers reaffirmed Sunday that everyone else on the team is healthy and ready to play in Game 1.