Born in Rosario, it was quite evident that when Andres Alejandro Diaz made his debut as a professional footballer, it would be for local club Rosario Central. And so in 2003, Andres wore Rosario Central colours and came out to play on his Primera Division debut. In four years with Rosario, Andres played almost 80 games and scored 3 times. In 2007, he went to Portugal to sign with Portuguese powerhouse, SL Benfica but as soon as he went in, he just got one game before they sent him to Banfield on an 18-month loan period that will see him start with the 2008 Clausura.