With his team trailing 94-92, Bryant misfired on a potential game-tying jump shot along the baseline and came down on the foot of Hawks defender Dahntay Jones.
Bryant remained on the floor for several moments before limping off and leaving the game on crutches.
The five-time NBA champion would not speculate on his chances of playing on Friday at Indiana and vented his displeasure about the injury instead.
"First and foremost, I think the officials really need to protect shooters," Bryant told reporters. "Defensive players, you can contest shots but you can't walk underneath players.
"There's no rhyme or reason why I should come down anywhere near somebody's foot."
Jones, who had a previous incident where he was given a foul for tripping Bryant during the 2009 Western Conference Finals, defended himself on Twitter.
"Tape doesn't lie," Jones tweeted. "(Bryant's) ankle was turned on the floor after the leg kick out that knocked him off balance. I would never try to hurt the man."