I am actually ok with his defending, it's always been average, but overall has been a net positive with what he has added to our attack..
This season he hasn't been as impactful with his ball progression and I think comes down to having Rice instead of Partey in the middle. Zinchenko works best as more of a support role in the middle, playing off the 6 and dropping into pockets of space to pick out passes. Now it feels like he has had to take on more responsibility there and hasn't struggle to make an impact.