Just seems obvious to me Theo that he must have the ability necessary, but he needs to play against grown men who have learnt how to make a defender's life really difficult. He has to re-learn when it is safe and wise to do what. If you are one of the better players in age-group football, you get away with stuff that an old-pro will catch you out on. Give him some second team games, give him some bench time and bring him on if and when things are going better for your team. Play him in a cup game or two. Let him build his own confidence.
If he's your worst defender ever I reckon you haven't been paying proper attention. If he were already a made player in Pep's eyes, like Cole Palmer, he'd be staying at City. Mbete is in the process of being made. Do the job you've taken on. For a start if he's learned his trade at City he is used to winning and his team being on top - being dropped into a struggling team of seasoned pros has to be a culture shock. Second half of the season you might have a gem. You don't get a ready-made Colwill (who Chelsea could put in their back four now if they needed) every time you jam your sticky fingers in the lucky bag.
If he's your worst defender ever I reckon you haven't been paying proper attention. If he were already a made player in Pep's eyes, like Cole Palmer, he'd be staying at City. Mbete is in the process of being made. Do the job you've taken on. For a start if he's learned his trade at City he is used to winning and his team being on top - being dropped into a struggling team of seasoned pros has to be a culture shock. Second half of the season you might have a gem. You don't get a ready-made Colwill (who Chelsea could put in their back four now if they needed) every time you jam your sticky fingers in the lucky bag.