warn and fine them if they perform 6.3 or lower. This can improve their work rate and determination, probably the consistency too. If you notice your assistant feedback is always saying a certain player is passing straight to the opposition or constantly getting burned, talk to him about it after the game. If a player in the first team under the age of 25 is not progressing well in terms of improved attributes, harass him about training, or if any coaches indicate he needs more focus in training, in the player development tab. All of these will help.
I have turned players from "balanced" personality to "resilient" from doing things like this. Sometimes it even requires an over the top fine or punishment. For example I had some excellent Brazilian regen striker, he thought he was tough stuff, bigger than the team. Demanded a trade, demanded a new contract, starting playing extremely poorly (5.6 rating 30 minutes into matches). I fined him 2 weeks salary, sent him to reserves, refused new contract, refused to sell, constantly screamed at him with aggressive tones and next thing I knew he improved dramatically not only in attitude, but in attributes also. You have to know your players though, and treat each one on an individual basis. Don't just scream and max fine all of them for similar occurrences.