Miller, who was cleared to play against the Celtics, initially met with a doctor in Detroit on Friday night after he took a hit near his head during the Heat's 106-92 victory over the Pistons. A Heat team spokesman described Miller's post-game doctor's visit as "standard procedure" and also confirmed the team's primary physician in Miami was consulted before Miller was cleared in advance of Sunday's game in Boston.
It turned out to be one of Miller's worst shooting games of the season. He played 25 minutes and had nine rebounds but missed four of five shots from the field, including the potential game-tying 3-pointer just before time expired.
Miller was one of the first Heat players to leave the locker room after the game.
"Shoot, [it was] an open shot," Miller said of his attempt from the top of the key. "I've got to make it."
Miller took another hard blow Sunday when he was buckled by a Kevin Garnett screen midway through the third quarter. Miller fell to the floor and got up slowly as play continued. Heat guard Dwyane Wade was assessed a flagrant foul with 7:18 left in the third quarter for running over to Garnett and extending his forearm as the two pursued a rebound in the lane after Miller fell.
The altercation drew players from both teams into the lane, with Wade and Garnett having to be separated as referees sorted out the flagrant foul call. Wade said after the game he did not intentionally hit Garnett in retaliation for the hard screen set on Miller.
Miller played the rest of the third quarter, but was on the bench for most of the fourth until he entered in the final minute. In the Heat's previous game, Miller played 30 minutes against Detroit and finished with 16 points and three rebounds.
Miller entered Sunday's game averaging 6.3 points and five rebounds while shooting 42.3 percent from 3-point range after missing the first two months of the season following October thumb surgery.
Michael Wallace covers the NBA for ESPN.com.