what do you guys think about trying him out at LB?
Its the best solution possible.
Firstly, matuidi is very reliable defensively, so he needs just to focus in covering both the lm and ronaldo. And thats it.
We dont need crosses from him because ronaldo plays on his side, and we dont need him making much runs because He just needs to play it safe to the closest player near him and keep it cool.
Also this way, he doesnt harm our midfield with his funky offensive skills and leaves the position to the more skilled rabiot and betancur.
Win win.
As a cover left back is a good solution to both problems of left back depth and midfield balance