Álvarez made his professional debut in Argentina for River Plate in 1998. In 2002, he moved to Serie B to play for Reggina. However, he returned to the Americas a year later, joining Morelia of the Liga MX. Álvarez played a significant role for the team that season, playing in 16 games, 13 starts, and scoring three goals and helped them reach the league final but lost to Monterrey. He remained a consistent starter for the team and started a total of 60 games for the team, scoring nine goals.

In the 2010 draft of the Liga MX, Álvarez was bought by Tigres UANL in a high-profile transfer. A starter under Ricardo Ferretti, he became a key in the team’s offensive for the Apertura 2011 Championship. He scored the goal of the 1-0 victory in the first leg of the finals against Santos Laguna. Tigres won the Liga MX Championship for the third time after 29 years. Álvarez, along with Danilinho, Héctor Mancilla and Lucas Lobos in the attack, became the so-called “Cuatro Fantásticos” (“Fantastic Four”) of the Liga MX.

In 2012, Álvarez became a naturalized Mexican citizen, having settled in Mexico in 2003. He was called up to Mexico national team on 23 February for a friendly against Colombia; Mexico lost 2-0.

On December 14, 2014, he received a red card along with teammates Hernán Burbano and Nahuel Guzmán in the Apertura 2014 final against Club América. Álvarez and his team lost 3–0 in the final at the Estadio Azteca. Álvarez was a regular starter in the 2015 Copa Libertadores. In the group stage, Tigres played against his former team River Plate and scored the second goal of the 2-2 draw in the home game. Tigres would eventually reached to the finals and lose to River Plate.