I think the real limit here should come in terms of the salary cap. They said they were reworking it to make the cap an actual challenge to stay under and if you are bringing guys back it should be expensive, and get more expensive each time. Also, each year the player should get worse and worse becoming less worth the millions he is getting paid. I have always been against adding false limits to things though and limiting the number of players you could do this to would be adding a false limit. When the real limiting factors are so easily available that is what they should use.