Can an undisciplined player influence the overall performance of the team?

[Igms]

Hi everybody. I brought a player for 130M an despite my scout team, he is a bad one who lacks the training and loses matchs. I punish him and he accepts it everytime it happens. My question is: is it possible that the existence of this player could reduce my team performance? The last games that he played my team strangly got grades between 6 and 7, lost games or draw then. Attetion: anybody is unhappy... all my players are fine, and didn't talk to me about him. Is anybody could help me with this question? Tks a lot.