You are waiving the rights to the player to allow them to proceed through the wire and re-sign them to the IR. That's cutting them. What doesn't make sense, through, is why you even have to do that. If a player of yours gets hurt, he should stay yours, moving that player to IR should create the roster space.
Once you make the 53 roster you can do that. Im not arguing it makes sense...it may or may not...but its different when its not in season.