I think this is something Guardiola is really making a point of this season.
For a long time the players have hidden behind Guardiola and "the system". Whenever we lose its Pep's fault. Aguero misses a penalty in the spurs CL game and its Peps fault. We give up 2 easy goals in the Liverpool CL game and its Peps fault because Gundogan was on the pitch 60 yards away. Laporte gifts Lyon 2 goals, multiple players miss open nets and its Pep's fault.
I also think that's why people are complaining about not being attached to individuals in this team - the focus has always been on the system and the collective.
This season he seems to he saying its up to the players. If you make a mistake at the back, you're out of the team until someone else does.
If the 11 on the pitch get in a mess, sort it out yourselves, don't expect me to take you off so you're out of the spotlight, he picked a good enough team to win, he prepared them all week, showed them the opposition weaknesses - go win the game.
If the players want to win everything they need to learn some personal responsibility, win games themselves, not expect Pep to do it for them or hide behind him when they lose, because he can't be on the pitch with them to hold their hands when things get tough.
Some players will rise to that challenge - Stones seems like one of them already - and that is when we will finally replace the "big characters" that people want.