The Giants announced the move on Wednesday and said they placed cornerback Prince Amukamara on injured reserve with a torn biceps. Amukamara was injured Monday night in a loss to Indianapolis.
Brown was waived on Tuesday after playing seven games with the Ravens. He has played in 46 NFL games with two starts.
New York also signed safety Kyle Sebetic to its practice squad. He was with the Giants in training camp this summer.
Online: www.pro32.ap.org and www.twitter.com/AP-NFL