Shael,
Take a look at the Pogba touches video. Ignore Pogba and pay close attention to Kroos. You'd see some disturbing attributes YOU used to complain about regarding Yaya. On multiple occasions, he shoesc no interest in joining in the defensive effort. Watch his actions when Griezmann scores. He just stands above the 18, watching proceedings lime a paying fan.
Not that it was his job to mark Griezmann. But there is Pogba with the ball at the corner inside his team's box and he leisurely just watches.
On 2 occasions you see Hector and Draxler run past him to go hell on defense, Kroos is barely jogging. On the Second it was Can and someone else. He often showed no interest in getting back into play once the ball got behind him.
These are worrying traits. Bit Domalino is trying to paper over it by saying he was playing 10, whatever that means. These are worrying characteristics regardless of where he plays.
Effort when your team is out of position should be none negotiable for everyone. Talk less a Central midfielder.
I've seen plenty of Kroos and there is no escaping that he's not great defensively. He doesn't cover ground quickly, he's not agressive enough at winning it back, and yes, he can appear lazy when his team are out of possession.
However, the role I'd expect him to play for us is very similar to how Pirlo played the majority of his career. A deep lying playmaker who has two players in front of him pressing the ball. You could never accuse Pirlo of being Kante or Makele when defending, but he's one of the best midfielders of his generation because he's so good on the ball.
He plays in a specialist position. The best in the world currently in that role are Busquets, Alonso and Kroos. Busquets is the best defensively, but on the ball Kroos is leagues ahead of the other two.
If we played Kroos as one of two central midfielders in a 442 and expect him to tackle, dictate play and score 20 a season like Yaya did in 2014, he'd be a disaster. He's not got the engine, the pace, the power, the agression to play that role. Unfortunately neither has Yaya anymore.
But as a specialist in that Pivote role if he had Gundogan and Fernandinho in front of him pressing high up the pitch, I think his quality on the ball would be so good that his defensive limitations wouldn't be exposed too often. Sure, he'd get caught out every so often, but I think he'd make far more positive contributions than bad.
Guardiola has worked with him and knows his qualities, so on this occasion it's perfectly legitimate to say "In Pep we trust".