Davis played 4 minutes, 20 seconds and scored the Magic's first basket before being taken out of the game. It was not clear how he was injured.
"You never want to see a teammate injured," Orlando guard JJ Redick said after the Magic lost their seventh straight, 113-97. "We have played without him before and we just have to continue to roll with the punches, and guys are going to have to step up.'
Davis came into the game averaging 15.5 points and 7.5 rebounds in 40 games.
Both teams came into the game short-handed as Orlando was without leading scorer Aaron Afflalo and the Knicks were without veteran backup point guard Jason Kidd.
Kidd, who sat out the second half of Sunday's win over Atlanta, was again out with a sore lower back.
Coach Mike Woodson said Kidd may have tweaked his back playing extended minutes with starting point guard Raymond Felton out recently. An 18-year veteran, Kidd has averaged 28.5 minutes this season -- roughly three to five minutes more than Woodson wants.
Afflalo, who is averaging 16.7 points, missed his second straight game with a strained left calf.