#3 Eric Bailly
Chris Smalling and Victor Lindelof have been entrusted to protect Manchester United's back line most this season but they've performed poorly. Central defence is the team's clear main problem area yet Bailly has managed only 3 starts.
Bailly was substituted embarrassingly early against Newcastle and it summed up his relationship with his manager perfectly. Since his arrival, Mourinho hasn't fancied the Ivorian defender and his appearances have slowly diminished in number.
On his day, however, he is far superior to Mourinho's other options in the position: a confident Bailly is powerful, energetic, and commanding, as opposed to the nervy and clumsy Smalling, Lindelof, and Phil Jones. Discussion of moves to Chelsea and Arsenal have already started in the media but Bailly still has time to win back his place in the first-team at Old Trafford.