Napoli defender Elseid Hysaj was denied a move to Chelsea in the summer, his agent claims.
He told Radio Kiss Kiss: “Those who criticise him probably never make mistakes, but the rest of us are mere mortals.
“Without that clause, he probably would have gone to Chelsea this summer.
“People forget that he was one of the best two or three full-backs in Europe last season.
“Then it just takes two or three matches for him to become a donkey.
“I always say to let everyone talk and then respond on the pitch.”