I disagree mate. Parker has been a stalwart for us in previous seasons. I don't think anyone expected him to struggle like he has since coming back. If he was playing to his previous level, we wouldn't be having this conversation... Who can predict form?
I don't think Parker is showing a huge lack of form (though he has dipped), I just don't think he's suited to 'possession football'. Parker is still great at tracking, harrying players and breaking up play, but previously his remit was simply, 'win it and pass to Modric'. When we play against teams who sit back, he's now expected to play forward balls and create something, but he's just not that kind of player. His pirouettes are him trying to turn while shielding the ball, because that's his mentality, to protect.
Parker has his skillz, but he's not a massively technical player and therefore isn't so creative with the ball, whereas Sandro can tackle as well as Parker, his vision and passing is better too. Don't get me wrong, Parker has been massive for us, and there will be times we need Parker in there, but when teams like Lyon concede the midfield, there is no battle for Parker to win.