Argentina are likely to stick with their 4-3-3, with Di Maria and Messi as deadly wide attackers who drift inside, supplied by Javier Pastore, and Sergio Aguero as a dangerous presence both on the ground and in the air.
Chile will probably stick with their flexible 4-1-3-2 but whether Charles Aranguiz and Arturo Vidal press high up the field or drop back alongside Diaz will be the key tactical decision.
To press or not to press – Chile’s dilemma
Why Chile might hold back
Chile and Jorge Sampaoli need to neutralise the triple Argentinean threat of Messi, Di Maria and Pastore who put Paraguay to the sword. The most important player to do that is Marcelo Diaz, the holding midfielder who will have the job of exerting control over the midfield space that Di Maria and Messi love to exploit, and preventing the kind of lightning break that saw Paraguay thrashed.
Gary Medel may also step up into that space, being a harrying defensive midfielder by instinct, but he must be wary of being sucked out of position, especially by Messi dropping deep, and exposing his defensive partner to overlapping runners. Chile have a personnel problem at centre-back after Jara’s ban, with José Rojas being notoriously slow. There have been mutterings that he could be replaced by Francisco Silva but Sampaoli has publicly supported him.
For that reason Diaz and Medel may need help, either from Aranguiz and Vidal hanging back or the Chilean full-backs not bombing forward in their customary manner. The central midfielders would be the safer option, in order not to leave space for Argentina’s full-backs who love to push forward, and in order to maintain Chile’s own counter-attacking threat on the wings.
Why Chile might push forward
The question is do Chile have the discipline to play defensive? Although their progress to the final has had a touch of pragmatism, they haven’t compromised their all-out attack yet. Vidal and Aranguiz are key to that philosophy, loving to pressure high up the field and win attacking opportunities.
A higher-risk strategy, but one which comes naturally to this Chilean side, would be to target the supply to the Argentinean attack, especially Mascherano who often drops back between his centre-backs to start the attacks of the Albiceleste.
Alexis Sanchez’s seemingly infinite running is a good fit for that kind of pressing, but Eduardo Vargas and Jorge Valdivia are less natural harriers. Vidal and Aranguiz and the Chilean full-backs are involved in the full Bielsa-inspired press and might hope to force the kind of mistake that led to Paraguay’s solitary goal, but it would leave a horrible mismatch of attacking and defensive talent if Argentina broke beyond the press.
Vargas and Valdivia meanwhile would hope to make use of the space that can open up between Argentina’s defensive and attacking units when Mascherano drops back and Pastore pushes up. That can leave Lucas Biglia isolated in the middle of the pitch and he may have trouble covering the space. Vargas showed how deadly he can be from that range against Peru, while Valdivia is having the tournament of his life so far and can run the show if given time and space.
Vidal and Aranguiz the key men
Sampaoli’s choice should be easy to see on Saturday night – will he choose to drop Vidal and Aranguiz back to protect his back four, or will they push up high and hope to hit Argentina before they can hit back? As a neutral, the most exciting prospect is definitely the latter, which could lead to the most insanely attacking final to a major tournament in years.