Postecoglou sets Celtic always in a formation with four defenders, but instead of ordering the full-backs to come out high and provide width, he requires them to often come down the center with the ball and assist the midfielders as inverted wing-backs. Although based on their statistics it appears that Celtic play a 1-4-2-3-1 or at most a 1-4-3-3 formation, they mostly play with only one central midfielder in the pivot role (McGregor) when building the action. This is a key position for Celtic Postecoglou both in the possession phase, when he supports the offensive and plays between the lines, but also after losing the ball, when he is entrusted with the tasks of actively fighting for the ball.
Defensively Celtic usually play a high line of defenders with the side defenders positioned wide to push off the opponent’s wingers, so the free wide spaces behind them must be covered by the defensive midfielder and the central-backs. After receiving the ball the side defenders (Taylor, Ralston) do not stick to the sideline but appear in the middle of the field to create a positional advantage in this area with the additional task of playing between the lines and engaging the rivals’ wingers. From a tactical point of view, Celtic’s wing-backs can be seen as additional central midfielders. When a wing-back comes inside, one of the central midfielders can move either outside or forward and during this time the winger always makes an aggressive move down the wing or towards the penalty area. The effect of this approach and the rotation of positions in the middle is also a better preparation for the attack after the ball has been intercepted, because the nominal central midfielders go either to a wider or a higher position early on after winning the ball.
In the build-up phase it is the midfielders who dictate the tempo and manage the flow of the game. When the midfielders receive the ball their job is to break the line and only when further passing options arise do they not hesitate to play risky direct passes. The pivot always plays deeper and even in the final phase of an offensive action he is in the spaces between the lines operating in the middle of the field.
However in situations of numerical superiority Celtic’s players do not force the offensive by looking for conditions to beat defenders with passes, dribbling or running duels. Celtic Postecoglou also uses a lot of vertical direct plays from the defensive line to move the ball right into the offensive third.
Around the rivals’ box Celtic is very aggressive, constantly rotating positions and aiming to get into free positions by all available ways. The eight in Postecoglou’s team (Rogic/Turnbull) then acts as a space investigator, in which he actively rotates with other players and sometimes even to break the last line of resistance of the rivals, the eight tries to pull a defender out of formation. All this to create free space between the defenders. An important role in this phase is also played by the wingers, who then descend actively from the side to the center and very aggressively towards the opponent’s goal. These movements are also repetitive: wingers coming inside from far away and constant rotation in the center.
