Copeland was stabbed in the elbow and abdomen outside a New York nightclub early Wednesday morning. He had surgery in New York and stayed behind as his teammates traveled to Detroit for Friday's game.
Copeland has promised to work hard to make a full recovery and apologized for being out so late on a game night. The attack occurred at about 4 a.m.
The Pacers wore blue headbands, one of Copeland's trademarks, as they beat the Knicks later Wednesday.
Oklahoma City coach Scott Brooks says forward Serge Ibaka will miss at least the rest of the regular season with an injured right knee.