Mendy is the answer he was rated one of the best left backs in europe and all the top clubs were after him , he has had a horrific time with injuries and to write him off at this stage is premature , after the first six games this season he had the most assists in the Premier league and although many appear to think he is a useless defender but the modern wing back is now judged first on their attacking ability and Mendy is one of the best in the business. His social media antics shouldnt deter from his ability on the pitch , all that really matters is his popularity with his team mates and he appears to a welcome addition when he is a around the club.
Right now with Mendy out , Laporte has to cover that position he is the only left handed natural defender with genuine pace in the squad , we have three other decent centre backs to make up a back four (when they are fit)