Walter Adrián Luján Samuel (born Walter Adrián Luján; 23 March 1978) is an Argentine footballer who plays for Internazionale. Samuel has been regarded as one of football's toughest defenders, with team-mate and Inter captain Javier Zanetti referring to him as the "hardest player" he has played with. Samuel has also been regarded as the most aggressive and dirtiest partner at centre back by his solid former team mate Lucio. Gifted with natural power and pace, Samuel's game has developed and at Inter a new level of maturity has evolved. He played a key role in Inter's treble success under José Mourinho and is a regular fixture in the Argentinian national side. His strong, uncompromising style of play has earnt him the nickname Il Muro ("The Wall").