The Jets did a good job limiting Shonn Greene's carries last year to keep him fresh for the Playoffs. I am not sure this was by design. It seems like the coaching staff just was enthralled by LaDainian Tomlinson's fast start and wanted to feed LT the football. Preserving Greene had a good effect, though. Shonn averaged only 12.3 carries per game.
A guy who seeks contact like Greene has a limited shelf life. The hits pile up and can wear down a power back late in the year. They also give backs shorter productive years. There are certain things a back can do like avoid unnecessary shots before while in the process of stepping out of bounds, but you do not want Greene to change his style. If he gets less aggressive, he will be less productive.
That is why I get the team taking Bilal Powell for once LaDainian Tomlinson retires. Greene and Powell have similar styles. Together, they might be able to pound on a defense for an entire game, wearing down the front while staying fresh individually and productive both late in the season and later in their careers than they otherwise might be.