Here's some names:
Balotelli
Lovren
Di Maria
Falcao
Mangala
I'd probably say Falcao or Balotelli. Remember the ridiculous hype Falcao got on transfer deadline day? Ridiculous when you look back on it. As for Balotelli, he's been abysmal all season - barely works at all. I read a stat that this season he's only covered twice as much ground as Mignolet