When you think of the Dragoes' defensive personnel, you think of the suspect Rolando, the other Maicon and the veteran goalkeeper Helton.
Sandro, a product of the Atletico Paranaense academy and former Santos loanee, is the unheralded force in the Portistas' great season to date.
While his rapid progress has reached a temporary halt due to the recurrence of an injury (via ESPN), he is Vitor Pereira's No. 1 choice when fit.
The first thing of note when watching Sandro play is his physical presence. As he grew he looked a little lanky despite standing at under 6'0" in height all his life, but since leaving Santos he's added bulk and strength without sacrificing speed.
He already has elite instincts as a full-back and knows when to stay on his feet and when to go to ground—a decision process many young full-backs get horribly wrong early in their career.
Tackling properly is an art, and Sandro is close to mastering it, as he rarely gets caught "square on" by an attacker and is rarely seen dropping off due to any reluctance to make a challenge.
Going forward, he can commit defenders and attract double coverage from the opposition. He's traditional in his methods, preferring to hit the byline for a cross rather than dance around and risk losing possession.
While his streaking last-man challenges are impressive on the eye, Sandro's ability to sense when to go forward and when not to needs refinement.
He makes those challenges because he has to, but seasoned defenders rarely find themselves in that position. It will come with time, and there's also an argument to suggest he works a double shift at times due to James Rodriguez's exclusively attacking thought process.