Im going to say it, I really don't see why so many have an issue with him. People say he dawdles on the ball but I say he's composed. He's also not afraid to create angles to pass into unlike a lot of others who only pass left, right or straight in front or behind
I do wish he'd sit in front of the back 4 more though and stop playing so high up
On the face of it he looks "OK" because he doesn't really do much, and that's precisely the problem.
Defensively though his positioning and awareness is awful. So many times when the opposition have the ball in our half he ball watches. I lost count the amount of times Sigurdsson ran off the back of him and he didn't even notice/follow.
Juve spotted him as a weak link, and i'd say Everton did the same. All the attacking work came down the left channel.
His build up play from defense is also just not good enough, he doesn't command the ball and when he does receive it he's happy to play square 5 yard balls.
If he does try to advance up the pitch he thinks he's Pogba and tries to hold them off as they press, but he doesn't have the quick feet not the acceleration to get away.
I just don't see what he does for us that nobody else can. I'd much rather have Herrera in the team, in his small cameo he won the ball back more times than Matic seemed to in the whole match.