Sunday’s disappointment at Norwich has once again led to meltdown in the twitter-sphere, and those Gooners with hair-trigger emotions cast words around with impotent rage. But not primarily at the anaemic performance of the last hour.

Yes that’s right – it’s more key injuries. Obviously, it is Alexis’s hamstring ping that has sent supporters into a tailspin, due to its apparently avoidable nature. With all the talk of red zones and tight hamstrings, it was inevitable that the man who seemingly hasn’t stopped running since 2013 was going to pick up an injury sooner or later unless he was rested.

Certainly Wenger’s post-match reaction was a combination of Homer Simpson-esque “d’oh” and frustration at having taken Alexis at his word when the Chilean had declared himself fit. Apparently Alexis suggested it was just from a kick on the thigh, but Le boss made it pretty clear that he doubted that diagnosis.

Needless to say the knives were out for the manager, justifiably criticising his reluctance to rest a man who clearly needed it. And although top players are increasingly needed to monitor their own physical condition (and some are good at erring on the side of caution… *cough* Daniel Sturridge *cough*), is it a surprise to anyone that Alexis might let his enthusiasm cloud his better judgement?

Accordingly, it is probably right to leave this particular mess at Arsene’s door – though it needs to be asked whether Sanchez was ‘softened-up’ by being shoved headlong into a concrete pit by their idiot centre-half…entirely unnecessary and fundamentally very dangerous. Technically a red card offence, apparently. Things were also probably not helped by Jon Moss once again inhabiting his own world of laissez-faire random decision generation. Either way, while the medium term repercussions of this will probably be painful, it was ultimately another earlier injury that proved more important within the game itself. Koscielny hobbling off meant drafting in a distinctly under-cooked Gabriel, who made an awful error for Norwich’s momentum shifting equaliser. The change also seemed to unsettle the rest of the back line, with a decent start from both full-backs unravelling into the least convincing performance for a while.

Oh, and naturally, Cazorla finished the game ‘on one leg’. On top of that the team found itself reliant on the hastily returning Ramsey and Oxlade-Chamberlain, and others like Giroud are clearly in need of a breather.

So how culpable is the manager? Of course, his hand was partially forced by a multitude of injuries elsewhere. With so many injured, the opportunity to rotate has not been there, inevitably leading to more injuries. It is the same old Arsenal story. And none of us know why…and in the absence of any concrete information, most blame the man in charge. Which may be entirely justified.

The strongest argument for this is that over Wenger’s tenure the players have changed, the doctors and physios have mostly changed, as have many of the coaches, while the problems remain…the only common denominator is the manager and his methods. This is certainly supported by Dutch rent-a-quote fitness coach Raymond Verheijen, who manages to get himself in the newspapers every time Arsenal have a spate of injuries, suggesting that Wenger is personally responsible for them all.

However, Wenger’s retort is well aimed.

“This guy looks like he knows absolutely everything. I am amazed that he knows more than all our physios and all our doctors.”

Certainly Verheijen seems to know the inner workings of the coaching methods of every major English club in remarkable detail, and apparently knew what his boss Gary Speed’s dying wish for the Welsh team was (for Verheijen to become manager). While his experience would suggest he isn’t talking from a position of ignorance, there is clearly a continual agenda to raise his personal profile (and sometimes plug his book).

There is probably some credence in the idea that as an older manager Wenger may not be the quickest to adopt new discoveries and approaches, but this increasingly accepted view that he is a manager who fundamentally causes injuries is fairly strongly contradicted by the very few injuries suffered by the teams he managed in the first half of his Arsenal tenure. The game may have moved on in terms of technique, finance, competition and the balance of power, but human physiology hasn’t dramatically changed in the last decade. Neither have the physical demands at the absolute top level. No one can tell me that Ashley Cole, Thierry Henry, Patrick Vieira or Jose Antonio Reyes did much less high intensity work than Gibbs, Walcott, Wilshere or Oxlade-Chamberlain, yet their injury records are poles apart.

This is not to suggest that the club shouldn’t constantly review its modus operandi to find that extra 2%, but rather that one has to put carte Blanche accusations through the simple logic test. All oranges are fruit, but not all fruit are oranges. Lazy correlations don’t help anyone.

Mistakes have been made. Players have been rushed back far too often, and in this sense at least the club appears to be learning to err on the side of caution, except in times of a manpower crisis such as now. And we all know Wenger often comes down on the wrong side of the risk/reward balance when selecting only partially fit key men.

For me, however, the most valid criticism to be levelled at the manager is regarding squad composition.

As we discussed on last week’s podcast, the absence of u21 players on the fringes (who don’t count against squad limits) pushing for selection results in a smaller overall pool of first team options than our rivals. Even with the under-achieving side of six years ago, we had the likes of Ramsey, Wilshere, Walcott, Vela, Bendtner, Gibbs and Djourou all as ‘homegrown’ u21 options. None were first choice, but all were able to fit in and contribute. All were full internationals before the age of 22. The current equivalent options are Chambers, Oxlade-Chamberlain and then those on loan like Akpom, Zelalem, Hayden, Maitland-Niles and maybe Toral (with less than 10 first team appearances between all five). With today’s squad size limitations this pool of u21s is more important than ever, and yet we have the weakest crop in over a decade. Of course this has been influenced by these squad limitations massively inflating the price of players under the age of under 21, but the club is on solid enough an economic footing to compete in this market. Some of the ‘project youth’ baby has departed with the bathwater.

There is also an even more fundamental issue. We have a number of injury prone players in the squad (as Wenger himself admitted in his press conference), and that number is too many under the aforementioned squad size limits.

Today’s emergent statistic is that every single outfield player at the club has missed at least one game due to injury in 2015 – except Joel Campbell (who was on loan for the first half the year and has barely played for the club). What is key, however is how many of those have been significant injuries, and how many have been recurrences of or related to previous injuries. As Mark covered last week, Ramsey, The Ox and Walcott as comparative regulars, seem vulnerable to similar types of injuries which could be affected by training, and certainly by playing style, and as such have to be both anticipated and endured. All three are important enough to persevere with. Kieran Gibbs probably fits into this category too, and possibly Flamini, although both are less vital and slightly more injury prone when playing regularly (though Gibbs seems to have benefitted from a reduction in game time).  There are of course others, like Coquelin and Welbeck whose injuries have both stemmed from ongoing minor issues, but should be corrected on their return.

As part of a balanced squad this isn’t too bad. But then we add Arteta, Rosicky and Wilshere. Our Spanish captain seems to have declined to the point where he can’t stay fit enough when playing to get up to speed in terms of performance level, and this has been as slow, steady decline that seems irreversible. Rosicky is the king of the remarkable resurgence from an extraordinary array of leg injuries, seemingly missing several months a season, but then picking up as if nothing has happened on his return. Jack has the biggest question mark hanging over him. Can he adapt his style of play to minimise the seemly endless succession of ankle problems, or can he get strong enough to withstand them?

Either way, with a squad already too lean in terms of potential contributors due to the lack of push from the under 21s, we cannot afford to carry three senior professionals who will year after year be injured more than not, particularly on top of those with a pre-disposition to picking up less serious but fairly regular muscle injuries. This is particularly pronounced because the vast majority of both categories are midfielders. Carrying one or two injury prone players is hard enough to deal with in a game of limited squad sizes, but carrying twice that in the same position is just unsustainable. And frankly, unless they are regular starters, or at least potentially regular starters, there is very little justification in retaining the services of those with seemingly chronic injury issues.

Because as we have seen this season, as so many times before, if two-thirds of your fringe players are injured, it renders rotation impossible, or at best, unpalatable, meaning your real key men cannot get the occasional rest and recovery time they need.

And whether we like it or not, that DOES stop squarely at Arsene Wenger’s door.