He's not diving around anymore because he doesn't have to. Pellegrini's set up often put the CB's in situations where they had to charge out and make a challenge to cut out an attack before it started because otherwise we were fucked.
Kompany, Otamendi, Mangala, Demichelis - they all jumped into tackles and went off their feet too often in the last 3 years.
Now, with a proper defensive structure, Otamendi doesn't have to make those last ditch tackles. Maybe Pep has had a word about staying on his feet, but thats a secondary thing - the main one is he's not being put in the situation where he feels he needs to dive in.
Kompany, Otamendi, Mangala, Demichelis - they all jumped into tackles and went off their feet too often in the last 3 years.
Now, with a proper defensive structure, Otamendi doesn't have to make those last ditch tackles. Maybe Pep has had a word about staying on his feet, but thats a secondary thing - the main one is he's not being put in the situation where he feels he needs to dive in.