Under huge pressure to win on home soil, Brazil have been given a middling draw in the group stages: not a group of death by any means, but not the sort of gimme handed to France and Belgium either. This should be Brazil's biggest test.On the opening day, Brazil were surprised by Croatia's energy and organisation, repeatedly finding themselves opened up by runs in behind their adventurous full-backs. They dragged themselves back into the game thanks to two sensational performances: one by Oscar in an unfamiliar right-sided role; the other by the referee, who gave Brazil the benefit of a series of borderline outrageous calls.Luis Felipe Scolari's selection will be interesting. His response to Brazil's bewildering array of talent has been to settle on a first 11 and stick to it, with the result that Brazil look cohesive, strong and focused. So what does he do about two of his attackers, wide man Hulk and striker Fred, being completely ineffective in the first match? Chelsea's sinewy offensive midfielder Willian probably has the strongest claim to a place.Mexico were expected to finish second to Brazil in Group A, and duly picked up three points against chaotic Cameroon. They won 1-0, but had two perfectly good goals by the excellent Giovani dos Santos chalked off before then, and were much the better team. What they won't be today is overawed by the opposition. Mexico famously beat Brazil in the final at the London 2012 Olympics and will be well up for springing a shock again. Expect a particularly entertaining game if Mexico retain the wing-backs system they used to dismantle Cameroon: the four wide defenders on the pitch will all look to run past their opposite number and attack.