Wade had been expected to play after a sore knee caused him to miss Monday's practice and Tuesday morning's shootaround.
"I'm going to be good to go no matter what," said Wade, who banged knees with Bulls center Kurt Thomas on Saturday. "I'm trying to get the swelling out. After two days of rest I feel better."
James also missed the morning workout and had been labeled a game-time decision with a sprained ankle suffered in a loss to the Los Angeles Clippers. After getting treatment Monday, James declared himself ready to play. The two-time reigning MVP had missed two straight games, losses to Denver and Chicago.
"No matter who's on the floor ... we've got to find a way to get a win versus one of the hottest teams in the league," Wade said prior to Tuesday's game.
The third member of the Heat's Big Three, Chris Bosh, missed the game with a sprained left ankle suffered against the Bulls.
"He's making progress," Heat coach Erik Spoelstra said of Bosh. "He's moving around better today. Certainly not ready to run and explode off of it, but if you saw the footage, the replay of it, we're just thankful it's minor at this point."
"We do have versatility on the roster," Spoelstra said. "This is probably the time it'll show the most, playing guys that weren't necessarily playing big minutes, they'll be able to step up and have their opportunity."
The Hawks have won six of their past seven games and bring a four-game road winning streak to Miami.
Brian Windhorst covers the Miami Heat for ESPN.com. Information from The Associated Press was used in this report.