If they sent all three down, they would have only had a single callup for the rest of the season unless there was an emergency. (sbnation.com)
Hoffenheim attacker Roberto Firmino got his first callup to the Selecao last month, and now has his first goal, an impressive long range strike in his country's 2 - 1 win over Austria. (caughtoffside.com)
I think it was mostly because they only have a limited number of callups. (sbnation.com)