In this task, you are given a context paragraph, a question based on that and corresponding answer of a question. Your task is to generate supporting fact/knowledge from context paragraph which helps in answering a given question.

Walter Adrian Lujan Samuel (] ; born Walter Adrian Lujan; 23 March 1978) is a retired Argentine professional footballer. Gifted with natural power and good defensive skills, Samuel has been regarded as one of the best centre-backs of his generation, and as one of football's toughest defenders, with former international teammate and Inter captain Javier Zanetti referring to him as the "hardest player" he has played with. Question: What is the birthday of the Argentine defender Associazione Sportiva Roma signed before the 2001 season? Answer: 23 March 1978
Walter Adrian Lujan Samuel ; born Walter Adrian Lujan; 23 March 1978 is a retired Argentine professional footballer.