While James (hamstring) went through some on-court work during Thursday's non-contact practice, Wade (leg) and Allen (ankle) were mostly limited to stretching and conditioning. The team announced after Friday morning's shootaround that none of them would play in this game.
All three injuries are considered minor, but the Heat (58-16) want to make sure they're healthy come the playoffs. Miami already has clinched the Eastern Conference's top seed.
"We still have time to work on our game. We want our guys to get rhythm," coach Erik Spoelstra said. "But they have to deal with these minor injuries right now. We're being very proactive and very aggressive. We're going to take care of them."
Point guard Mario Chalmers, though, did participate in practice Friday and was upgraded to a game-time decision. He's missed the last three games with a sprained ankle.
Wade and James have sat out the last two. Allen, meanwhile, was hurt during Tuesday's 102-90 loss to New York.
"We want to get those guys back as soon as possible," forward Udonis Haslem said. "But we have some time, eight games left? We have some time to get them back."
If Chalmers plays, he likely would be joined in the starting backcourt by Mike Miller while Norris Cole heads back to a reserve role. Rashard Lewis could start again in place of James along with Haslem and Chris Bosh in the frontcourt. Bosh, averaging 16.7 points, has scored 23 in each of the last two games.
"The No. 1 thing, obviously, is try to get as healthy as we can," Spoelstra said. "Obviously, that's a priority. From there, we have time to still try to improve -- not just stay in rhythm, but to improve, and also get these guys an opportunity that haven't been getting minutes to play in these meaningful minutes."
Even without its top players, Miami should still have a good chance against Charlotte (18-57). The Heat have outscored the Bobcats by average of 14.7 points during their run in the series, including a 109-77 rout March 24.
James had 32 points, 10 assists and eight rebounds that day while Wade sat out due to knee troubles.
Although the Bobcats average 93.5 points to rank 27th in the league, they have posted 103.2 in winning five of six at home. Charlotte, though, used a stifling defensive display to beat Philadelphia 88-83 on Wednesday, holding the 76ers to 35.1 percent shooting.
"We rotated, we helped, we talked and we were together," said Kemba Walker, who had 17 points, 10 assists and five steals. "That's what it's all about. If a guy gets beat, he expects a teammate to help him. That's what we did."
Gerald Henderson also came up big again with 24 points and Josh McRoberts added 12 and a career-high 16 boards. Henderson is averaging 23.6 points -- 8.2 more than his season mark -- on 52.4 percent shooting over the last 12 games.
Despite the Bobcats' offensive improvements in Charlotte, they'll likely be tested by the Heat, who have limited opponents to 90.8 points per game in winning 15 of 16 on the road.