Anthony became entangled with a teammate during five-on-five drills in an afternoon practice. He appeared to be in discomfort but walked off under his own power.
He did not return to practice and also sat out on Tuesday.
"I tried to make a move, I tried to plant. My foot slipped," Anthony said. "I kind of hyperextended my leg a little, my knee a little bit. But I'm fine."
The All-Star small forward underwent surgery to repair knee and elbow injuries in the offseason. He hyperextended the opposite knee on Monday.
Late last week, Anthony said that he'll enter training camp feeling "better this season than I've felt in a long long time."
Monday was just the fourth day of practice since the lockout ended. The Knicks play the first of their two preseason games on Saturday in Newark, N.J., against the Nets.
Antony is not worried about the injury.
"I'm good, no worries," he said.
Knicks coach Mike D'Antoni expected Anthony to return to the court in the next few days.
"He's playing tomorrow. If not, it's the next day," D'Antoni had said Monday. "I think he just went out just to ice it down and be ready to go tomorrow."
He even joked that Anthony was feigning an injury to get out of practice.
"He's been going great... why risk it?" the coach said, turning serious. "There's really no risk but why not wait until tomorrow."
Ian Begley is a regular contributor to ESPNNewYork.com.