I started this team in division V so i'm not sure how IV is on older players but I went out and found 2 great players that are 34 years old CHEAP! and put them into my Division games to help my team win. These players has not lost any skill since joining my team... as a matter of fact 1 gained some points. I don't really know when they start to lose their talent, however as long as you shop around for a backup to take his place when he starts to go down you can dump and continue with your pre-developed backup and not lose a beat.