Got caught a few times in possession last night which is most likely why Pep subbed him. I'm sure he will be frustrated with that performance & no doubt Pep will leave him out next game now that Akanji is fit. There's no doubt he's going to be a quality player & I expect him to come back stronger.
He was keeping the ball to long when he had an easy pass which in previous games he did, think he needs a rest mentally to reset! He has played a lot of important games and was great.