Born in Capitán Bermúdez, Santa Fe Province, Ruben started his career with Rosario Central in 2004. In the 2006 Apertura tournament he scored seven goals in 17 matches to be the team's top scorer, and this brought him to the attention of several major clubs in Argentina and Europe, with Club Atlético River Plate eventually winning the battle and paying US$7.5 million for his signature, alongside teammates Juan Ojeda and Cristian Villagra. After a short spell, Manuel Pellegrini's Villarreal CF purchased Ruben for $7 million in January 2008, immediately loaning him to fellow La Liga side Recreativo de Huelva until 30 June. He made his league debut in Spain on the 27th, appearing as a substitute and being booked in the 1–3 home loss against Getafe CF. The loan was renewed for the 2008–09 season, but Ruben scored just three times as the Andalusians were relegated. After returning to Villarreal, he spent the vast majority of the year with the reserves, which were having their first experience in the Segunda División. In mid-January 2010, Villarreal agreed to sell Ruben to Wigan Athletic of the Premier League after the player had helped the reserves to the fourth place with nine league goals, good enough for joint-third. Although the player agreed personal terms with Wigan, the clubs could not reach an agreement and the deal fell through. On 7 February 2010, more than two years after his purchase, Ruben played his first league game with Villarreal's main squad, appearing six minutes at RCD Mallorca. On 9 January of the following year, while starting in the place of injured Nilmar, he scored against Real Madrid to make it 2–1 for the Valencians, who were eventually defeated at the Santiago Bernabéu Stadium. On 13 July 2012, Ruben signed a five-year contract with Ukrainian club FC Dynamo Kyiv for a €14 million fee. He scored his first goal for his new team on 3 November, netting the first in a 2–0 home win against SC Tavriya Simferopol. After a spell in the French Ligue 1 with Thonon Évian F.C. where he failed to meet expectations as that particular type of football did not suit his style, Ruben joined Liga MX side Tigres UANL on 18 June 2014 on a one-year loan from Dynamo. He made his competitive debut on 9 July, playing the whole of a 1–4 loss to Monarcas Morelia in the Supercopa MX. Ruben returned to Rosario Central on 24 December 2014, initially on a temporary deal. He scored a career-best 21 goals in his first year and was named team captain. On 11 January 2019, Ruben joined Brazilian club Club Athletico Paranaense on a year-long loan.
International career
Ruben made his debut for Argentina in an unofficial pre-Olympic preparation match against Guatemala in February 2008, scoring once in a 5–0 win. His first official appearance took place on 5 June 2011 in a friendly with Poland, and he netted the 1–1 equaliser in an eventual 1–2 loss.
