The 30-year-old is played in a more defensive role at Camp Nou, but received plenty of plaudits for his campaign in the middle of the park for Argentina.
Redknapp wrote in the Daily Mail: "Javier Mascherano has proven at this World Cup that he is a midfielder and not a defender. Why on earth do Barcelona play him as a centre back?
"He is not tall enough for the position and it does not suit him, but when Mascherano is in midfield he is a different animal."
The former Liverpool player came close to clinching a World Cup winners' medal, but Argentina missed out in the final following a 1-0 defeat to Germany at the Maracana last night.