Do you mean the star ratings for players on the team reports? I think (not 100% sure) that it all depends on the reputation of your club so under 5 stars doesn't mean they're a bad player, for instance in my Liverpool save both Gerrard and Torres are only 4 stars and are brilliant for me, also Agger etc. are around 2-3 stars but they aren't bad players, it's just that the club reputation is high.