After scoring 15 goals in the first 13 games of the Apertura 2007 tournament, Denis was called up to join the Argentina national team for the first two matches of the 2010 FIFA World Cup qualification, against Chile and Venezuela.

In November 2011, Atalanta director Pierpaolo Marino confirmed that Denis would join the club on a permanent deal after the end of the player's loan contract.

[6] On 27 April 2015, Denis was banned for five matches after he burst into the opposition dressing room the day before and punched Empoli defender Lorenzo Tonelli.

[7] On 30 January 2016, Denis scored on his final appearance for Atalanta, a 1–1 draw against Sassuolo, before returning to play for Independiente in Argentina.

[8][9] Denis signed a two-year contract with Serie C club Reggina on 22 August 2019, making a return to Italy after three years.

[10] He was part of the squad that won promotion to Serie B, and played in the Italian second division with the Calabrians as well, before leaving Reggina by the end of the 2021–22 season.

A powerful striker, who is capable of playing anywhere along the front-line, and of using his physique to hold up the ball for teammates, Denis is known for his goalscoring, as well as ability in the air.