Young.
I don't disike him. If he was a squad player, filling in at full back or out wide for when the clear 1st choice options are rested, I wouldn't mind. But he's the captain, so he has more responsibility than just being the most senior player. Yet that's all he has. He is the clear 1st choice, yet he is the most limited player in the squad. He's not particular good at anything anymore except working hard.
I don't understand how he starts over Darmian and Valencia. Both can actually play the position and defend and both have good technique. Neither of them just resort to punting it into touch under the slightest press. Neither are good enough either, but are better defenders than Young.