That’s because Pep (and other managers) don’t look at substitutions like fans do. Football is a simple game in many ways but from Pep’s POV it’s all about fine intricacies and complicated tactics. Every player has a different role in every different game and within ten minute spells within every different game, that changes the pattern of play, the spaces on the pitch and how they move the opposition around the pitch. It’s not about “if Bernardo and David were still on the pitch we would have created more because they’re creative players” or “if de Bruyne had played centrally he would have been more effective”. Every move Pep makes has a detailed reason behind it from ‘X player’ will occupy certain spaces and make certain runs to create space for ‘Y player’ to do other things to exploit that space, going off what Pep has seen from the way the opposition has played in the game so far. It’s not a case of “go out there and get us back in the game mate”. With all Pep’s subs yesterday we started to create more and more chances, he probably saw that Norwich had eight players occupying the space where our attacking midfielders were so that’s why he took them all out of the game and put de Bruyne on to fit a different role going off how Norwich were defending. It worked to a certain extent because we created a lot of opportunities in the last 20mins but our finishing was terrible.