So he was injured up until the Saints game? Did not know that. Also, I thought there was a way to keep a player on the team without suiting him up. So he has to be injured or else he's on the PS?
He was inactive for the Texans game and didn't get any snaps against the Patriots or the Titans. There are 53 players on the roster but the team only dresses 45 on gameday. For the Texans game, Greene was one of the last 8. For the next two, they just didn't give him any carries. To make it on the practice squad, the Jets would have had to cut him. Then, 31 teams would have had to have passed on putting a waiver claim on him, not likely. If that happened, he would have been PS eligible. If the Jets would have wanted him to play in a game after that, they would have had to cut someone on the active roster to make room for him, and listed him as active for the game.