Xavi vs Gary Medel
It is rare Spain fail to dominate a midfield, the main reason behind that is Xavi. He is central in their tiki-taka style, and if you stop him playing, you are half way there in stopping Spain playing. On Friday, the Netherlands managed to restrain his talents and prevent him doing his usual game, dictating the tempo and territory of the match. This was integral in stopping Spain at the source and Chile will be looking at their success and looking to emulate that themselves.
Looking at Chile's midfield, it is probably Cardiff City midfielder Gary Medel's job to stop Xavi and co playing. He will need to get in the faces of Spain and look to prevent them time and space on the ball, with the aim of winning the ball off them and freeing Chile's forwards to go on the counter-attack. Many have tried and failed that and Medel will be against the odds to do so, but he will certainly not be afraid to fly into the tackles and get stuck into Spain. If he gets on top of Xavi, Chile might just cause a shock, if not, they could be in for a long night.
Jordi Alba vs Alexis Sanchez
They may be teammates at Barcelona, but on Wednesday night that will be put to one side in the Maracana. Alexis Sanchez is to Chile what Neymar is to Brazil. He is quick, athletic, a great dribbler and a keen eye for goal. If anyone knows that better than most, it is Jordi Alba. Sanchez will know the Spanish team inside out, and therefore where they can be exploited. One area is the left-back position.
Jordi Alba is incredibly quick. He has unbelievable stamina and can get up and down Spain's left side all match without getting tired. Yet his obsession with getting forward leaves a lot of space behind him, space that can easily be exploited by Sanchez. The Chilean forward will likely place himself on the left of Spain's defence, as clearly that is where Alba will be missing and a lot of space be. Should Chile play the counter-attack, Sanchez could be key and Alba will need to be aware of his defensive responsibilities. If not, Sanchez could expose Spain's lack of pace in defence like Robben did on Friday.
Cesc Fabregas vs Gonzalo Jara
New Chelsea signing is rumoured to be included in Del Bosque's starting XI for the clash at the Maracana. After missing out on the first game, he will be desperate to make an impact on the match and the result. Fabregas is likely to replace fellow Chelsea target Diego Costa and play in the false number nine role that worked so well during the successful Euro 2012 campaign.
If he does play there, that will leave Chile's centre-backs a problem. Gonzalo Jara is a certainty to start there, and he will not have anyone to mark. Creating a problem, does he step into the midfield and look to help out his outnumbered midfielders, or does he stand his ground and look to protect the space rather than the players. This is a difficult problem for the defenders as they won't know whether to stick or twist, and whatever they decided to do will have its risks. If Fabregas does play in the false striker role, he could cause a lot of problems for Jara and the Chile defence.