At age 12, he began playing for the youth team of Club Bahiense del Norte, together with future NBA star Emanuel Ginóbili.

The following year, he accepted a scholarship offer from Temple University in Philadelphia, but stayed in Argentina during the 1995–96 season, playing for Estudiantes de Bahía Blanca.

After his participation in the 1996 Youth Panamerican Tournament in Puerto Rico, where he represented the junior national team of Argentina, he moved to Philadelphia where he played for the Temple Owls college team for 4 years under Hall of Fame coach John Chaney, and finished his career as the #2 player in the NCAA in steals (he is currently in fifth place in career steals).

On February 22, 2001, he was traded along with Toni Kukoč, Nazr Mohammed and Theo Ratliff to the Atlanta Hawks, in exchange for Roshown McLeod and Dikembe Mutombo.

In Europe, Sánchez won the EuroLeague championship in the 2001–02 season, while playing with the Greek Basket League club Panathinaikos.

Sánchez's performance at the 2006 FIBA World Championship was quite satisfactory, with the Argentine press choosing him as the most outstanding player of the team.