Earlier in the season Iraola brought him back at centre back in preference to Senesi, and played Kerkez at LB. I don't know if he'd do that now because Senesi has had a long run and he's most aggressive in following strikers into midfield.
But otherwise I'd play Kelly ahead of Senesi and ahead of Kerkez (not at the same time haha). He makes the odd mistake (maybe could have prevented the head-back for the 2nd goal last week), but so does everyone (how many times a game does Senesi dive in in midfield?) And no-one can burst forward as aggressively as Kerkez, but Kelly plays the role he's told, within a system. So last year when he was stationary with the ball at his feet, waiting for something to happen in front, it was because that was his role. Likewise. when passing endlessly across the back 4 under Parker.
For me he showed his ability at the beginning of this season when opponents used the acres of space in midfield to run straight at our back 4, and he used his pace to jockey them.
He's still one of my first 3 on the teamsheet.