A promising left-back who was brought initially on loan from Boca Juniors on 11 January 2007. Seven months later Liverpool made the transfer permanent for an eventual cost of £1.675 million as well as being entitled to 50% of any future transfer fee for Gabriel Paletta who moved the opposite way to Boca. Insúa started two League matches, at Portsmouth and Fulham, towards the end of the 2006/07 season and a year later he was picked to play in the final three League matches. His reward was a new three-year contract which would tie him to the club until June 2011. Insúa continued to impress in the 2008/09 season, making 11 starts. He made his international debut for Argentina in a dramatic World Cup qualifier against Peru on 10 October 2009 which Argentina won in the ninety-third minute keeping their hopes on track. In 2009/10 Insúa made a big breakthrough in terms of competitive matches played, 44, as that number was more than twice what he had achieved as a total over the previous three seasons. He would have played more games if he hadn't tore quadriceps in his thigh on 4 April against Birmingham. Insúa had started to struggle a bit in games in the second part of the season and was criticised by fans and media. He should have been rested when his confidence was low but Liverpool lacked cover in the left-back position as Fabio Aurélio was most of the time out injured.
Many saw a bright future ahead for Insúa, who was still only 21-years-old but had already featured in 62 games for the first team. New boss Roy Hodgson reportedly wanted to keep him at Liverpool and Insúa wanted to stay but managing director, Christian Purslow, who was infamous in his time at the club for meddling with transfers, wanted him out! Liverpool and Fiorentina agreed a fee believed to be £5 million on 17 July 2010. However, early in August the Italian club's sporting director revealed that the deal had fallen through because they had been unable to agree terms with the Argentinian. On the final day of August 2010 Insúa joined Turkish club Galatasaray on loan for the 2010/11 season. Meanwhile Liverpool had brought in Hodgson's former player at Fulham, Paul Konchesky, to play at left-back as well as re-signing injury-prone Aurélio. Few could make sense of the club's transfer policy at the time and no wonder! Insúa played 16 Super Lig matches for Galatasaray, but team manager, Gheorghe Hagi, who replaced Frank Rijkaard in October 2010, did not take the option to buy him. Before the start of 2011/12 Jose Enrique was brought in as first-choice left-back while Insúa left Liverpool permanently in the last week of August 2011 to sign a five-year contract with Portuguese club Sporting Lisbon. Insúa had an adventurous first season in Portugal, playing in 24 league fixtures and 12 Europa League matches as Sporting topped Group D before progressing to the semi-final stage where they were beaten by Athletic Bilbao. Insúa scored four times during this excellent continental campaign, where as he had scored just a single goal at his previous European clubs; Liverpool and Galatasaray. Insúa joined high-flying Atletico Madrid in January 2013.
only had half a season to impress in Spain, he only started two La Liga matches for Atletico Madrid and was more often than not an unused substitute. Before leaving Portugal for Spain, he had played in thirteen Primera Liga matches for Sporting Lisbon in 2012/13 plus five in the Europa League. He had no better fortune in 2013/14. Although Atlético became the Spanish champions for the first time since 1996, the full-back only played in 5 league matches. He did also play in the Copa del Rey four times including both legs of the semi-final against their city rivals Real. But Real won both legs, 3-0 at the Bernabéu and 2-0 at the Vicente Calderón. Insua was loaned to Rayo Vallecano for 2014/15 and at the end of this spell his contract with Atletico was terminated by mutual consent with one year remaining. He then joined German side VFB Stuttgart, where he suffered relegation from the Bundesliga in his first season but stayed to help them back up at the first attempt. He was again relegated with Stuttgart in 2018-19, when they lost a two legged play off to Union Berlin. For the first half of 2019/20 he was not a regular in Bundesliga 2 and as he was in the last year of his contract, he was allowed to join LA Galaxy on a free transfer on 2nd January 2020. After playing 22 MLS games Galaxy declined the option of extending his deal and on 16th February 2021 Insua agreed to join Argentine Primera club Aldosivi. He remained there for a year before joining Racing Club on a free transfer in January 2022.