ONE OF the biggest risks apparent in Celtic's squad when the summer transfer window closed was the depth and coherence of the central midfield.

In Ange Postecoglou’s favoured formation there are three midfield berths. 

One is a more defensive, central pivot (or '6'). Two positions then flank the pivot and are expected to work box-to-box as '8s' offering both defensive solidity and attacking flair.

There were two major concerns at the end of the summer window.

Firstly, there simply weren’t enough good quality midfielders in the squad. Especially those that offered attacking threat.

READ MORE: How Celtic could be affected by upcoming Japan and Australia international fixtures and what it means for Kyogo, Rogic and co.

In late August, it seemed Celtic had Callum McGregor, Tom Rogic and David Turnbull for two positions. But given it seemed, after Jablonec away, that McGregor was earmarked for the pivot role, that left a serious lack of 8s.

Secondly, neither of the first choices were natural number 8s. Both Rogic and Turnbull have been deployed further forward as attacking midfielders behind a striker (or '10s'). Neither resembled a box-to-box, dynamic, all-round midfielder.

And it seemed from early on McGregor’s ability to progress the ball from deep quickly and effectively saw him filling in as the 6 even though he was probably the most natural 8. What a pickle.

Add in that nobody quite knew how James McCarthy fitted into all this, and it just seemed an incoherent mess.

Where are we today?

What transpired is that McGregor, the best 8 has played nearly all season at 6 while the two 10s have played all season as 8s. Are you following?

McGregor and Turnbull have played more minutes than any other outfield player. Rogic is on track for breaking his total minutes for a season. All three have suffered an injury, and Turnbull is likely out for many months. Flogged to death, then. This is a highly physically demanding role in Postecoglou’s blueprint.

This has led to an unlikely renaissance for Bitton after three years cross-training to be a 5 to come back as a 6. McCarthy remains peripheral and Ismaila Soro is seemingly on the fast track out of town.

The January 'reset'

Postecoglou’s depleted and “Angeballed”-out squad limped into the winter break.

It is clear the manager recognises the risks that have become issues for large parts of the early season and set about addressing them with recruits in January.

Recruitment has, potentially, been smarter than in recent times. This is because:

1. Markets whose seasons are over have been targeted e.g. Japan and the USA

2. The clubs appear to be getting ridiculous value for money e.g. final fees for high potential young(ish) Japanese players like Reo Hatate, Yosuke Ideguchi and Daizen Maeda are reportedly no more than £5million total.

3. The business is subsequently being done early. None of Peter Lawwell’s famous last-minute deals. Three players were available for winter training restart.

READ MORE: Why Ryan Christie was perfect for Ange Postecoglou and Celtic

Further emphasising that McCarthy and Soro will not get much game-time is the purchase of Ideguchi, who fits the model of the deepest midfielder. This also suggests McGregor may be utilised more as an 8 in the second part of the season.

Postecoglou also confirmed that Hatate had been signed as a midfielder. He profiles very much like a box-to-box attacking player who also is happy getting involved in the rough stuff. Dare I say, like Ryan Christie.

And as we introduce the silent ghost hanging over this piece, rumours abound that Aussie Riley McGree may also be Parkhead bound. His playing style? A bit like Christie, according to Asian football experts.

What is a 'Ryan Christie'?

Christie’s move to Bournemouth left the squad without their most natural all-round midfielder.

To describe him using data we will map volume of defensive actions and total expected scoring contribution (this is expected goals, xG + expected assists, xA).

It would look something like this:

Celtic Way:

Here we plot the current midfielders; McGregor from 2019-20 when he was beside Scott Brown in central midfield and Christie from 2019-20 which was a productive season.

A “Christie” is getting involved in around 12 defensive actions per 90min while also averaging nearly 0.9 xG + xA per 90. That’s a lot of work.

What the chart shows is, firstly, isn’t Rogic doing well! The Australian has not played as a box-to-box midfielder much in his career, so kudos to him for adapting his role so effectively.

Secondly is that none of the other midfielders remotely resemble a “Christie”. Even the more advanced 2019-20 McGregor is more about ball progression than high-volume attacking threat and the midfield rough and tumble.

But this model gives an insight into what Postecoglou is looking for from Hatate, perhaps McGree, and possibly a once again repurposed McGregor.

The absence of Turnbull weakens Celtic in other ways. His range of passing and expert set-play delivery are not easily replaceable.

READ MORE: Reo Hatate scouted - The Ryan Christie replacement that can fill Celtic's midfield void

What the new guys should bring though is improved pressing capability; more variety in that sense, to spring against low-blocked defences; and more in-box threat as opposed to long-range shooting dependency (Turnbull takes 69 per cent of his shots outside the box). Christie was infamous for that too, of course, but was also excellent at breaking beyond the striker.

The problem of numbers as identified at the start has been addressed with the addition of Ideguchi and Hatate. The possible addition of a player like McGree may be required given the severity of Turnbull’s injury.

Those players have been personally identified by the manager knowing how he wants to fit the pieces into his system. That speaks to a greater level of coherence to come.

Given McGregor can perform well as either a 6 or 8, that Bitton has proven useful again, and that Rogic has surprised and delighted in a new role, then suddenly the midfield risks reduce before our eyes.

Now, quite whether one of those players is able to post the breadth of numbers Christie did, remains to be seen.