Comment and Analysis
The England international last featured for the Gunners in April but has gone under the knife and is set to miss a number of months following his latest setback.
The defender's loan move to the Black Cats didn't go over well with American soccer fans, but it has the potential to put him on track to fulfill his considerable promise.
Madrid missed out on signing its No. 1 transfer target of the summer by mere minutes - but why did it take so long for both clubs to try and close out a deal?