Nah,just a couple of daft gaffs that will be soon be ironed out with experience,he's been far from terrible.
Youre right about his potential though.
In my opinion Stones is literally just a confidence issue, simple as.
He has made mistakes when things aren't going to plan, especially when the players around him make mistakes and aren't where they should be. It's in these moments when he looks up and players aren't where they are supposed to be.
His confidence is low so when he's forced into making spur of the moment decisions he's taking too long or making the wrong one.
The Southampton goal is a perfect example because we all know Sané should have been in a different position to be open for a pass, Kompany should have been in a different position and open for a pass. But they weren't and he panicked and made a mistake.
vs. Barcelona, he makes a back pass Bravo would pick up every day, but Caballero isn't Bravo, he's 10m deeper and Suarez gets on the end of the pass.
I think it's purely a symptom of the change in club, in system, in the new manager.
Things like under hitting a pass against Leicester is a classic low on confidence thing - you're in two minds over it so you sort of hesitate and don't get the power through the ball.
As he spends more time with Pep and just gets used to being here, and gets more experience he'll just not get panicked. The decision Guardiola wants him to make will become second nature, he won't be caught in two minds, he won't lack conviction in it. He'll just do it.
The errors will just go away. There's no huge underlying cause, he's not being asked to do things he can't, he's just got to get used to it.
I'm actually more concerned about things like his level of aggression.