Journalist Art de Roche believes that Arsenal already have the long-term replacement for one struggling star on the books at the Emirates Stadium. Oleksandr Zinchenko has endured a difficult season at Arsenal. The left-back has had an injury-hit campaign, and has struggled to produce his best on a consistent basis when he has been fit. There is even now an argument that he has fallen behind Jakub Kiwior in the pecking order after the Pole was handed the start against Bayern Munich recently. Zinchenko came back into the team to face Aston Villa on Sunday and once again fell short of expectation…