Manchester City - Eliaquim Mangala
Manchester City were tipped for domestic success this season but defensive frailties have so far hindered that progress.
With Vincent Kompany again struggling for fitness, Javi Garcia has been asked to fill in at the back, but he is no replacement for the City skipper.
A commanding centre-back is required to fill in the gap when Kompany is absent and Eliaquim Mangala can be that man.
With a £42m release clause, the young Frenchman is unlikely to come cheap but the 22-year-old would represent a long term investment and may even succeed Kompany as captain in the future.
If City want their title charge to succeed, they need a defender.