Regardless of an injury or not, he was poor.
And to me it's clear that his knees problems took away his outstading athleticism, which was probably the most important part of his game.
He's just not as explosive and dynamic now.
As much as I like him, and he's a nice guy, I'd ship him away, because we need someone better to be a backup at the position. I'd rather invest on Pereyra as a CM.