Lionel Messi (Argentina)
After celebrating his birthday on Tuesday, Lionel Messi ran out for his country to face Nigeria on Wednesday and duly scored for the third successive World Cup game"netting his third and fourth goals of the competition as he helped Argentina to a 3-2 win. Messi was in prime form throughout the group stage games but now the big games really begin"there can be no slip-ups if Argentina want to reach next month's final at the Maracana. To achieve that goal, Messi's team-mates will need to step up to the plate, as surely the Barcelona star cannot continue to make the difference every single game.
Xherdan Shaqiri (Switzerland)
Switzerland might not have the magic of Lionel Messi, but in Xherdan Shaqiri they have a player who is capable of producing the goods on the biggest stage of all. The former FC Basel star scored a stunning hat-trick to help his nation book a last-16 tie with Argentina , following Wednesday's 3-0 win over Honduras in Manaus. He is usually at the heart of everything that Swiss do in attack. He links brilliantly with the front man and has so far shown a lot of composure in front of goal. If Switzerland are to go further then Shaqiri will have to play a big part in this massive game.