Calum Chambers needs a rest
This leads us seamlessly onto the next lesson we learned. Calum Chambers is a talented individual, of that there is no doubt. But the youngster is proving to be bit of a liability and, in fairness, it’s not all through fault of his own.
Chambers was recruited in the summer from Southampton as a first-team regular of the future but, such were Wenger’s failings to address his key problems, the 19-year-old has already made 20 appearances for his new club.
He has spent most of the season stationed at full-back, a position in which he often looks lost, and should really have been removed from the firing line in the recent defeat to Swansea. And, for that, the manager must shoulder the blame.
That severe test will have shredded the confidence of Chambers, whose yellow card count - seven to be precise - had already suggested he is struggling to cope sufficiently with the rigours of playing so regularly.
Chambers was required to move into the centre of defence, his most natural position, against Stoke owing to yet more injuries and was given his marching orders following two more bookings. Is Chambers indisciplined or is he just fighting against the tide?