How Celtic's back three shape change helped Ange Postecoglou overcome deep defensive 'crab football'

The Hoops were missing even more first-team players than usual against St Johnstone and Postecoglou opted for a slightly different shape in response.

Necessity is the mother of invention and all that — but this wasn’t a manager slicing and dicing his tactics and ditching the process for a ‘pragmatic’ solution to player availability issues. 

Postecoglou’s philosophy isn’t chained inexorably to the 4-3-3. It never has been. He has used other shapes in his career and, as a driven and knowledgable coach, will do so again — to think that wouldn’t happen at Celtic at some stage is probably a bit foolish.

With Australia, his 3-2-4-1 was implemented to keep the attacking players in attack and create a midfield overload but also to add a bit of steel in the middle with dual pivots too. It helped get the best out of the '1', Tim Cahill, by encouraging early crosses to the back post.

With Celtic, a broad 3-4-1-2 allowed him to utilise all three of his main centre-backs, account for the lack of available wingers by pushing Josip Juranovic and Liam Scales up higher and, vitally, give Tom Rogic slightly more offensive freedom as the number 10 with mobile strikers ahead of him. 

It was pragmatic in its immediacy, sure, but the fundamental principles remain pretty much the same: press hard and press timely; move constantly to open up passing options; play forward-thinking, entertaining football. It's always been about the philosophy, the actual formation is simply a means to that end.

Celtic lined up from the start with a broad 3-4-1-2 shape

So how much of that did we see against St Johnstone?

On the face of it using a back three would seem to affect the very area it references the most. It does impact them, of course, and Stephen Welsh and Carl Starfelt were tasked with splitting across the box to help Vasilis Barkas start build-up as well as keeping a weathered eye on the theoretically exposed right and left flanks. Playing centre-back in a ball-dominant back three requires bravery, no doubt about it.

But really, in a three at the back system, the additional onus is almost always on the wide players. 

For Celtic on Sunday that was Juranovic and Scales. Both are defenders rather than wingers but they are composed and, albeit to varying degrees, equipped to play the possession-heavy inverted role Postecoglou favours when using a four at the back. 

In a back three, however, their more advanced position comes with added responsibility.

Against St Johnstone both players could afford to station themselves higher and wider than usual because they were the natural outlets with no wingers in front of them like in a 4-3-3.

Due to the dominant nature of Celtic's play this season, that was usually the case in Perth but, nonetheless, they were also expected to support the back three if St Johnstone won possession back to launch a counter-attack.

Juranovic passes, carries and dribbles v St Johnstone

Juranovic's set-piece responsibilities inflate his attacking contributions somewhat but the Croatian still clocked up decent numbers offensively while making his mark defensively too (three tackles, two interceptions, a clearance and not being dribbled past).

Scales' raw numbers are less impressive but the Irishman was still a persistent presence on the left, particularly in terms of counter-pressing (he led all players in total duration and duration per pressure).

 Scales passes, carries and dribbles v St Johnstone

As stated, both Juranovic and Scales are generally good on the ball but neither is particularly good at beating a man. This is where Postecoglou’s history comes in. While coaching Australia he used a 3-2-4-1 as a means of unleashing two attacking midfielders via running beyond the lone striker.

Against Saints, knowing they would defend resolutely if not expertly and rarely genuinely threaten in an attacking sense, Postecoglou opted to try to play to the strengths of Rogic, arguably his most in-form player and certainly the only one with experience of playing in a Postecoglou back-three system.

Like with Australia and his other club sides, it's all about passing forwards with Postecoglou. While the low-block approach adopted by most teams in Scotland has often led to what one regular viewer of TCW's Morning Briefing has termed 'crab football' as the team struggle to break through the lines without an early goal, there is still an obligation to try - and Rogic was once again the main force in doing so.

The 28-year-old rose to that task with match-high totals such as six key passes (all from open play), two direct assists, five passes into the box and 37 open play final-third passes as well as topping the xGChain. 

Dawson opposition half pressures and ball recoveries

Abada opposition half pressures and ball recoveries

In front of him, the strike duo conformed to the 'one high, one low' dynamic. Liel Abada provided the focal point for the Saints defence to concentrate on while Joey Dawson busied himself with dropping deeper as an additional passing option and, more effectively, as a useful pressing presence.

Behind him, while not offering the same overall qualities as Callum McGregor, having James McCarthy and Nir Bitton in midfield helped facilitate Rogic's freedom to roam around the final-third, inhabit the half-spaces and generally try to penetrate the St Johnstone rearguard with passes into the box.

Rogic final-third passes, shots and carries v St Johnstone

Was that fundamentally much different to what he is usually tasked with? Not particularly, but the adjustment in shape allowed Celtic to combat personnel issues without sacrificing the principles that make them a Postecoglou team. 

In the absence of McGregor - and, for the majority of the game, Kyogo - the manner of Celtic's win will likely have delighted the manager as much as the end result. 

And as for if we will see a similar shape adjustment and three-man defence after the winter break? As Postecoglou has said several times this season: it's always good to have options.