As every Tottenham Hotspur supporter at that end of the Emirates will remember, Theo Walcott was smiling as he left the pitch, enjoying a little malicious pleasure at their misfortune and not in any apparent distress. That is often the way with knee ligament injuries. At first, there is the sharp, excruciating burst of pain but it can pass within a minute or so, to the point the victim often believes he can actually carry on. It used to be a career-wrecker; now, even with the advancement of medical techniques, it is still the injury all footballers fear the most.
Football can be a cruel industry sometimes. Walcott did not make the cut when Fabio Capello announced his World Cup squad four years ago and, in 2006, he was the 17-year-old who was given a free ride by Sven-Goran Eriksson and, by his own admission, was completely out of his depth. Walcott spent a large part of that month walking around Baden-Baden capturing everything on a hand-held camera. Those memories remain his only involvement in a World Cup and now he must wait for Russia in 2018, when he will be 29, until he gets a chance to play his first minute in the biggest competition of all. It will not be his knee that is hurting the most; his mind will be aching.
For Arsenal, it is a grievous setback, first because he is one of their own but not least because once the emotion is taken out of it there is a hard-headed decision for Arsène Wenger to take about whether his current front-line is capable of sustaining an authentic title challenge. In the first half of the season, with Walcott missing large parts because of an abdominal problem, the issue was not quite so relevant. It is the run-in, however, that must concern Wenger, and the demands that are being placed on Olivier Giroud as the club's only orthodox striker bar Nicklas Bendtner, a player nobody at Arsenal wants to rely on.