There are many different facets that make up a decent professional footballer.

Some of these skills are universal - so they apply no matter what position they specialise in. Whether they are a defender or a striker, mental agility, fitness and a certain deftness of touch always helps, and a hunger to succeed is perhaps the most important.

Then there are skills that are intrinsically linked to the area they play in.

Strikers and midfielders need a certain awareness of where their opponents are, so they can use a yard to deliver the killing blow.

Defenders need a cool head, and a symptom of that is decision-making that can be used in the heat of competition. That millisecond that forces your hand - do you close down or do you track back? Do you give back to the keeper or do you attempt to pass out? Go to ground or stick tight?

These calls must be made in slivers of time that leave no room for dithering.

It is this that is holding Shkodran Mustafi back. In-depth stats revealed that Mustafi had in fact been our best performing player this season. The stats take into account aerial battles won/lost, tackles won/lost, passing percentage, ground ran and other small variables. Mustafi averaged higher than anyone else, but if you ask anyone how the German is performing, then the answer would be pretty much the same throughout.

While it isn’t as bad a s being a keeper, a defender lives and dies by mistakes. They are remembered for howlers, and defined by errors that lead to goals shipped. Mustafi is a fine athlete and in the air or on the deck, if he goes for the ball then the majority of the time - he wins it.

It is when he has time to make a decision that Mustafi needs to perform better. Too often he fails to nullify and make the decision that is common sense, and openings occur.

Mustafi is doing 90% of the job right, but it is the 10% that he will be remembered for. His Arsenal career needs rebuilding in terms of reputation, but he has the building blocks in his game.

He needs time to adapt to Emery’s instructions too, but time is a commodity that is not in plentiful supply at the top level.

Sink or swim. Let us hope that Mustafi starts to use his most important muscle more, rather than just all the others.