The hit -- termed a Flagrant Foul Penalty Two -- flattened the burly 7-foot Miami center with 6:29 remaining in the third quarter Thursday night.
"The contact by Jerry Stackhouse was clearly excessive and warrants a suspension," said Stu Jackson, the NBA's senior vice president of basketball operations.
Stackhouse plowed into O'Neal as O'Neal was going for a dunk, sending O'Neal tumbling into the photographers' row under the basket. O'Neal was restrained by teammate Dwyane Wade, likely preventing O'Neal from receiving his second technical foul of the night, which would have meant automatic ejection.
"My impression was my daughters tackle me harder when I come home," O'Neal said after game. "It actually felt pretty good."
Miami blasted Dallas, 98-74, evening the series at two games apiece.