"Baby looked fine, but he still has to go through a couple of tests this evening," Rivers said of Davis.
Davis suffered a concussion late in the third quarter of Game 5 of the Eastern Conference finals Wednesday in Orlando when he was struck in face by Magic center Dwight Howard's elbow.
Rivers said Davis experienced headaches after Game 5, but that they had subsided by the time the team watched film before the flight back to Boston.
After tumbling to the court when hit by Howard, Davis tried to get up as play moved to the other end of the court, only to fall again, and was clearly dazed when he finally got to his feet.
He took a few more steps, then staggered toward referee Joey Crawford, who wrapped his arms around Davis to keep him upright as play stopped with 9.7 seconds left in the period. Davis was tended to on the court for a few minutes, then walked to the Celtics' bench and eventually toward the locker room for evaluation. The hit also dislodged at least one of Davis' teeth.
"Never want to see anybody, especially a friend, go down like that," Howard said after the game.
The news Thursday was less encouraging on Marquis Daniels, who also suffered a concussion Wednesday and still looked shellshocked in the Boston locker room after the game.
"Marquis is not doing as well as Baby, I can tell you that," said Rivers. "Right now, I'm not too sure if he'll be ready. I would actually say he will not be ready, but that will be a game-time decision as well."
Daniels left the game early in the fourth quarter and -- like Davis -- was briefly unconscious.
Daniels got hit in the face while attempting to pass the ball (he was instead called for traveling). The little-used Daniels logged three minutes because of the rash of injuries and foul trouble.
During a conference call Thursday, Rivers also gave updates on other banged-up Celtics.
He said Rasheed Wallace continues to be bothered by a balky back, which remained so stiff he couldn't sit to watch film Thursday. Wallace hobbled to the locker room late in the fourth quarter Wednesday.
"Rasheed had been doing better, but he's not moving well at all today," said Rivers. "He felt a little better, but we watched film before getting on the plane as a group and he couldn't sit down. He stretched the whole time. He's feeling better, but he'll be a game-time decision."
Rivers also said that Rajon Rondo, who experienced muscle spasms in Game 4, is feeling fine. Rivers does not expect Rondo to be limited in his play.
Boston's coach was less enthusiastic about Tony Allen and his injured ankle, noting that it's really affecting his play and that the team might have to consider going in another direction for Game 6. Boston is already thin on guards and the few options at the position would be increasing minutes for Nate Robinson and Michael Finley, or activating former NBDL standout Oliver Lafayette.
Despite his team's health status, Rivers seems fine with the physical nature of the series. Following Game 5, as he surveyed the numerous ice packs in the Celtics locker room, he said to the team, "This is great, isn't it? This is the playoffs, this is what it should be about. Embrace this moment."
Chris Forsberg is the Celtics reporter for ESPNBoston.com. Follow him on Twitter.