A study provides an insight into Senna's capabilities

Marcos Senna is listed as a midfielder but his usefulness lies in his being a utility player capable of coming forward on attack, falling back to defend, and controlling midfield. He is strong in the air, very capable with free kicks, burns up the outside turf to slice in a cross, quick and decisive in his tackling, and shows some dribbling chops too, turning and twisting his way through defenders.

A time motion study (Bloomfield, et. al, 2007) analyzing purposeful movements of players playing specific positions show clear demarcations with midfielders covering more ground, defenders spending more time running backwards and laterally,and strikers turning more. Midfielders also play more short passes as defenders go for the long ball. They also spend significantly more time in skills such as tackling as compared to other positions. Strikers and defenders spend more time in high intensity physical contact as they use their body strength to advantage to head or break or make tackles.

A player like Senna probably washes out the significant differences between positions, successfully melding midfielding capabilities with aspects of defending and striking skills to create a physical and protean presence on the field.