League sources told ESPN at least one team official who tried to reach Rose before the game was unable to do so.
The Knicks released a statement shortly before tipoff saying Rose was not with the team and provided no further information.
Brandon Jennings started in place of Rose against New Orleans.
Knicks coach Jeff Hornacek did not mention anything about Rose's absence when he spoke with the media about two hours before tipoff.
Rose, 28, has averaged 17.3 points, 4.5 assists and 3.9 rebounds in 33 games for the Knicks. He missed four games earlier in the season due to back spasms but has been relatively healthy outside of the back ailments.
New York was further shorthanded when Carmelo?Anthony and Kyle O'Quinn were both ejected in the third quarter.
The Knicks were trailing 82-63 when the Pelicans called for a timeout. Before walking back to the Knicks' bench, Anthony had some words with an official, was assessed two technical fouls and was subsequently tossed by lead official Danny Crawford. Anthony finished with 18 points and 6 rebounds.
Less than two minutes after Anthony was tossed, O'Quinn joined him in the locker room after he was assessed a flagrant foul 2 for his hard foul on Anthony Davis with 1:16 remaining in the third quarter. O'Quinn slapped down hard on Davis as he was driving to the basket, sending the Pelicans' star flying into the stands.