Heat coach Erik Spoelstra said Allen missed the team's morning shootaround and indicated he was doubtful for the game.
The Heat, two games back of the Pacers for the East's top seed, are hoping to have Dwyane Wade back after missing two games with a sore Achilles. Wade is a game-time decision. He took part in the Heat's shootaround, and the team hopes he'll play.
Wade has been in and out of the lineup this season, having missed 19 games mostly as part of the Heat's proactive maintenance plan to help strengthen his troublesome right knee. But he's also been dealing with the left Achilles strain since last Wednesday, when he sustained the injury during Miami's loss in Boston.
The Heat initially said Wade had been dealing with a sprained ankle. But Wade clarified the injury when he met with reporters after Tuesday's practice, which was his first workout in four days.
Wade has averaged 19.3 points, 4.9 assists and 4.6 rebounds in 50 games this season. He had one of his best performances against the Pacers in Miami on Dec. 18, when he scored a season-high 32 points in the Heat's 97-94 victory.
"We know what Dwyane gives us," center Chris Bosh said. "We need him to be fresh in the mind and have a fresh body, too. We need him to play with the same intensity he's been playing with, maybe turn it up a little more, just keep being himself on offense, and we'll be all right."
Information from ESPN.com's Michael Wallace was used in this report.