The exclusion doesn't have much to do with Sandro's quality or apparent “World Class” categorization, really. Brazil are just spoiled for choice at the position - like the 2010 World Cup - where they had Maicon and Alves for the right, in contrast with a fairly mediocre (in relative terms) leftback in Michel Bastos (with Gilberto in a reserve leftback role). Marcelo starts for the team, obviously - weaker than Sandro in defensive terms, but one of the greatest attacking fullbacks of all time - let alone this era, and a perfect complement to Neymar. Filipe Luís is the reserve leftback - weaker than both Marcelo and Sandro in attack, and less balanced than the latter, but the perfect player for a more defensive-minded approach and Tite also seems to like him on a personal level as a member of the team (according to reports). It's like Cabrini missing out on an All-Time Italian XI spot because he has Facchetti and Maldini ahead of him. If Sandro was a rightback, he would be one of the first names on the team-sheet - ahead of both Fagner and Danilo.