By definition, a captain is a leader.

Every player puts his own stamp on what that means and as Vieira points out in Amy Lawrence’s excellent Invincibles book, his was a very different style of leadership to the vocal and dominant Tony Adams, preferring to lead by example.

If Mertesacker’s style involves leading by example it’s no surprise we got tonked by Monaco – his performance was abysmal.

Amid accusations of “too cocky” and “not wanting it enough” it’s easy to forget that Arsenal started brightly. This wasn’t a game where the attitude was wrong from the word go and the opposition were taken for granted.

Olivier Giroud and Danny Welbeck were both guilty of failing to hit the target with presentable early chances, a theme which was to pervade the whole game with Alexis in particular joining the parties guilty of failing to work the keeper.

For all the talk of Monaco’s brilliant defensive record, we had the chances in the first half hour to put a very different complexion on the tie.

Crucially though, we failed to take them.

Arsenal looked the more likely to score throughout the first half, but although we had our chances, Monaco generally kept things tight, defended as a team, and, when opportunities presented to go forward, go forward they did, but notably not in kamikaze numbers.

They made us work for every single thing we created.

How stark the contrast then to the opening goal.

WHERE WERE YOU?

38 minutes in, Welbeck goes into a half-hearted tackle and came out second best. At this point Monaco have three players out on the right wing, and just Moutinho and Kondogbia across the middle of the park, some distance out. Arsenal in contrast have their entire back four and two sitting midfielders in place, albeit both tugged out slightly towards the left side to cover the overload on the flanks.

Instead of working their numbers on the flank, the Ligue 1 side play two simple square passes so that Kondogbia has the ball at his feet. He takes a touch, strides forwards a couple of paces, and has the freedom of North London to smash a shot towards goal.

You can argue the deflection is unlucky, on another day it goes out for a corner. You can argue that Ospina should do better but deflection or no deflection he had still yet to move for the original shot and made no attempt to stick out an arm which may have made all the difference.

However, what seems incomprehensible to me is that Per Mertesacker, with no other players to worry about and his defensive partner alongside him for extra reassurance, made no effort to close the ball down.

Kondogbia didn’t exactly hide his intentions and, at this level, you cannot leave anything to chance.

I would lay my body on the line for this club.

I would run myself into the ground.

I would attempt to get out and block a shot clearly coming towards my goal. Is it so very much to ask the same of our defenders? Per Mertesacker – as Taylor Swift croons –  you should have been there!

It’s worth noting that in the immediate aftermath of that first goal, there was a bit of a sneak peek into the future, as panic and disarray set in. We started taking stupid chances in that final eight minutes of the half in desperation to get a goal back, apparently completely forgetting that this a 180 minute tie.

Another situation where we needed the captain to step in.

Another situation where he was found wanting.

MEA CULPA

If the first goal was at least in part unlucky (I’m being generous here, someone’s got to be!) then the second goal was just downright hideous from the stand-in skipper’s point of view.

Alexis loses the ball deep in the Monaco half, but Arsenal have seven players behind the ball against just three Monaco attackers, including the one on the ball still being jockeyed by the Chilean.

With three players in close attendance, Mertesacker makes the inexplicable decision to step up to make that four, in the process leaving Martial completely free with half the pitch to play in.

It is simple from then on for Monaco.

Laurent Koscielny is left two on one with no real prospect of support. Both Santi Cazorla and Hector Bellerin bust a gut to get back, but in the end the simple sidefoot pass around Koscielny and into Berbatov’s stride was played that half second too early to give them a chance.

Again, Ospina fails to make a difference, but the damage has been done much higher up the field.

THIRD TIME LUCKY? OR NOT…

So imagine the situation – you’ve just got a goal back in injury time of a game – the FIRST leg of a tie which lasts 180 minutes.

Do you (a) keep it tight and regroup for another day (b) protect what you have but remain alert for opportunities on the break (c) go completely gung-ho, throw everyone forward and hope for the best.

You can see it as we wait to kick off from the Ox’s goal; the adrenaline is pumping and no one is thinking clearly. It’s time for the captain to stand up. Except he allows option (c) to take over.

With five men ahead of the ball, Chamberlain stands on the ball and gets caught in possession. Koscielny is tracking Monaco’s only player ahead of the ball wide on the left, Chamberlain himself is chasing back in desperation. There are no Monaco players on their right wing whatsoever.

Even for Arsenal’s gung-ho approach, this situation can be controlled. It’s two on at least four, and in a relatively small area of the pitch.

Except that’s not quite how it plays out.

Alex gets caught ball watching a bit as Koscielny goes out to meet the wide player, at which point it is clear we have a problem on that side of the pitch.

Watching reruns of the goal, it strikes me how slow Mertesacker is to react to the situation unfolding in front of him.

There is one man bearing down on goal, from the right wing position and the German makes no attempt to move across, remaining marginally actually on the left hand side(!) and only walking right up until the final pass is played through.

Where is the anticipation? For a player with his (lack of) pace, in the last minute of a game, you have to be more alert to threat than that.

He breaks out into a jog for the first few yards before starting to really try to run when he finally realises that there is a player bearing down on goal. Even then, he fails to run directly enough at the winger, allowing him to get a shot away from just inside the box, a shot that ultimately squeezes in off Ospina’s fingers and puts the tie into the distance.

Of course the goalkeeper shouldn’t be beaten at that angle from that distance, not at this level, but as a centre back you should still be doing everything you can to stop the player getting the shot away.

On two such occasions on the biggest stage, Mertesacker has been found wanting.

STANDING UP TO BE COUNTED

Ultimately, three quarters of our back four actually played OK.

Koscielny didn’t have too much to do, with all three Monaco goals coming through Mertesacker and both full-backs acquitted themselves quite well at both ends of the field. The trouble is, the one who didn’t cost us three goals.

The manager will of course take some flack and it’s easy in retrospect to say we should have played Gabriel, but very few people can honestly say they disagreed with the line-up sent out to face Monaco.

No manager should expect his captain, a World Cup winner with over 100 caps, to so completely lose his head, stepping up to leave players free in behind and standing off the ball as the opposition approach your goal.

Arsene often talks about “in-game management” and that was something else completely missing – that is exactly where you need your captain to get everyone focussed and make sure that you’re taking the right approach for the situation.

So having just got back into the tie with a minute left, for example, not then going hell for leather for an equaliser at the expense of a further goal.

What we have we hold, and all that.

In the moments that matter, our stand-in skipper has been found seriously wanting.

We don’t see the manager’s alternative options in training, but it will be interesting to see if the German retains his place at the weekend, particularly against a pacy and mobile Everton attack. The shortest side in the Premier League, if it’s horses for courses, then Mertesacker is not necessarily the best choice for that game.

Regular readers will know that I am usually quite optimistic (an understatement perhaps!), and try to see the best in every player.

The trouble is, Per’s performance against Monaco had very little good to see.

Clearly well-liked and a character, it will be interesting to see if he can respond to what was a frankly abysmal performance on his part. It took some courage to front up to the media, that’s for sure.

Per’s height is an invaluable asset in certain types of games, and against certain types of opposition. The real hope is that with a couple of additional options at the back now, the manager can pick the best player for each scenario.

If he can return to the calm, experienced and consistent player that he has been most of the time he’s been at the club, that can only be a good thing.

Here’s hoping.

EVEREST

A combination of terrible anticipation and poor decision making from both our senior centre back and our goalkeeper meant that this tie, to all intents and purposes is over.

Three away goals at a club who have conceded just one in the entire group stage and has also conceded a solitary goal from their last ten league fixtures is not just a mountain to climb, it’s an Everest.

After recent years, you’d think we would appreciate the importance of still being in the tie at the end of the first leg.

Apparently not.

I’m calling it now – a “plucky” 2-0 win at Stade Louis II to see us eliminated, again, on away goals and the basis of a shocking first leg performance.

A shocking performance led by the captain, who gave the most shocking performance of all.

A miserable @nellypop13