Losing Leonard is disastrous for the Jets. Great player and the leader on the defense. The injury will definitely weaken the Jets' secondary to some degree.
He was great for the Ravens in 2008, he was one of the main reasons the Ravens made the AFC championship game as a #6 seed that year. I would have loved to have kept him instead of Dawan Landry. But Landry was cheaper and Leonard was looking for a big free agent contract.