Arsenal are in the market for a defender in the January transfer window, as an injury crisis at the back has made an addition necessary. Oleksandr Zinchenko missed last week’s defeat to Fulham, Jurrien Timber is out for the long-term and Takehiro Tomiyasu is at the Asia Cup, potentially leaving centre-back Jakub Kiwior as the only player who can fill in at left-back available right now. Jorrel Hato of Ajax has been linked, with Arsenal seemingly targeting a left-sided defender to boost their depth, but their financial fair play struggles will make a big-money transfer difficult to complete. Sm…