With players like Nemanja Vidic and Patrice Evra - longtime flag-bearers of the Manchester United back four - reaching an age at which performances tend to become more erratic, the Red Devils' defence has struggled.
Phil Jones, despite his vast experience as a Premier League player, is still not ready to be a starter. One doesn't need to look past last week's game versus Stoke to realise that he is still more than capable of putting in a horrible performance every once in a while.
Jones still looks a bit out of place in the team and he doesn't stay in his position. Even when deployed at centre-back, one often finds him in the attacking end shirking his defensive responsibilities.
Sure, every once in a while he can score a goal as great as he did against Norwich on Tuesday, but he needs to mature a bit more before he becomes a permanent fixture in the team.
Chris Smalling and Jonny Evans, I'm not so optimistic about. The latter, despite being at United for many years now, just doesn't look a good enough player. Simply put, he makes way too many mistakes.
I have more hope with Smalling, but I don't think he is good enough either. He looks un-coordinated and regularly gets skinned for pace. Furthermore, he has this weird tendency to completely misjudge the trajectory of the ball and often gives opposition teams unwarranted chances at goal.
While David De Gea, who has been absolutely sublime this seaso, has often been there to bail Smalling out, defenders at the top level shouldn't be making such basic mistakes. Furthermore, Smalling's ball control is abysmal and he seems to lack the necessary composure.
He gets flustered way too easily and is a liability on more nervy nights. The centre of defence needs reinforcements right away if United want to continue to challenge on the level that they traditionally do.
The flanks look a bit better. Rafael, I believe, is already a world-class player and can only get better. He has the pace, dribbling ability and the (new found) sense of urgency and positioning required to cement his place in the team and could be around for years to come.
On the left, however, Fabio and Alexander Buttner don't look up to Rafael's level. Buttner, I think, was a bad buy by Fergie. He looks a level beneath every other player on the field and seems like he is much better suited to being a winger than a full-back.
Fabio isn't bad either, but he isn't as good as his twin. Maybe in time he will mature to be as good - after all, he was the one who got the start in the Champions League final three years ago. The left has hope for the future.
United need reinforcements in defence. The old guard aren't quite what they used to be and the new guard haven't performed well enough to compensate.
United should look to bring in a couple of new centre-backs and a left-back if they want to be as rock solid as they were in 08-09.
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