Born in Quibdó, Chocó, Sánchez moved to a football school in Medellín and then onto Uruguayan club Danubio, where he signed his first professional contract in 2003 and was a teammate of Edinson Cavani.[4] However, he was released two years later, making no first-team appearances.
In the summer of 2005, Sánchez joined fellow league team River Plate Montevideo. He featured in 40 matches during his two-year spell, scoring once.
Valenciennes
In July 2007, Sánchez was bought by a group of investors and was assigned to Rangers de Talca, subsequently moving abroad for the first time in his career, by agreeing to a five-year deal with Ligue 1 side Valenciennes. He made his debut on 4 August, starting in a 3–1 home win against Toulouse.
Sánchez featured regularly for the side in his debut campaign, and was an ever-present figure during the following seasons. In March 2010, he damaged his anterior cruciate ligament, being sidelined nearly a year.[5]
After making 148 appearances for the club, scoring 8 goals in the league, Sánchez left the club in the summer of 2012 when his contract expired. After long negotiations with Bolton Wanderers[6] and West Ham United,[7] he failed to reach an agreement with any club, and subsequently rejoined his former club Valenciennes on 25 August 2012.[8]
Elche
On 16 August 2013, Sánchez signed a three-year deal with Spanish side Elche, freshly promoted to La Liga,[9] for a €3.7 million fee.[10] He made his debut on 24 August, starting in a 1–1 home draw against Real Sociedad.[11]
Aston Villa
On 15 August 2014, Aston Villa announced the signing of Sánchez on a four-year contract for an undisclosed fee reported to be around £4.7 million.[4][12] His first Villa appearance came eight days later when he replaced Charles N'Zogbia as a substitute in the 62nd minute of a goalless draw with Newcastle United at Villa Park.[13] He made his first start for the club in their 3–0 home defeat against Arsenal on 20 September, after illness had ruled out some of his teammates.[14] On 11 April 2015, he was sent off for two yellow cards as the team won 1–0 away to Tottenham Hotspur at White Hart Lane, causing him to miss their victory over Liverpool in the FA Cup semi-final eight days later.[15] Sánchez scored his first goal for Villa on 25 April, an 85th-minute deflected volleyed equaliser away to title holders Manchester City, but Fernandinho later netted a winner for City.[16] He made a 19-minute substitute appearance in the 2015 FA Cup Final on 30 May at Wembley Stadium in place of Ashley Westwood, in an eventual 4–0 loss to Arsenal.[17]
Fiorentina
On 10 August 2016, after Villa's relegation, Sánchez was loaned to Serie A club Fiorentina for a season.[18] He made his debut ten days later as a 65th-minute substitute for Milan Badelj in a 2–1 loss away to reigning champions Juventus on the first day of the season.[19] Eight days later, he made his first start in a 1–0 home win over Chievo, in which he scored the goal.[20] The move was made permanent at the end of the campaign.[21]
RCD Espanyol
On 31 January 2018, Sánchez returned to La Liga on loan to RCD Espanyol for the remainder of the season.[22] He made his debut four days later in a 1–1 home draw with FC Barcelona in the Derbi barceloní, playing the final four minutes in place of Léo Baptistão.[23]
West Ham United
On 9 August 2018, Sánchez signed a two-year deal with Premier League club West Ham United.[24] Having made just six appearances, in September 2018 he injured his knee in an EFL Cup game against Macclesfield Town requiring knee surgery.[25] He returned to the first team in May 2019, playing in their 3–0 home win against Southampton.[26][27] In June 2020, West Ham confirmed his departure from the club at the end of the month.[28]
Watford
On 4 March 2021, Sanchez joined English side Watford on a short-term deal until the end of the 2020–21 season.[29][30]
He left Watford at the end of the season following the expiration of his contract.[31]
International career
Sánchez made his international debut against Panama on 9 May 2007. He was then included in the 34-man provisional squad for the Copa América 2007, but later dropped for the final list. He was in the first team for all of Colombia's matches for 2010 FIFA World Cup qualification including the 2–1 victory over Argentina on 20 November 2007 in Bogotá. At the 2011 Copa América, he started three of Colombia's four matches as they reached the quarter-finals, coming into the team at the expense of Gustavo Bolívar after the opening game. He played in all five of Colombia's matches in the FIFA World Cup finals in Brazil in 2014, playing a defensive role which allowed James Rodríguez and Juan Cuadrado to be attacking midfielders.[4]
Sánchez was included in Colombia's squad for the 2015 Copa América, where he was credited with "dominating" Neymar during his man of the match performance in the 1–0 group stage defeat of Brazil in Santiago.[32][33]
His performance at the 2018 FIFA World Cup was poor. He got a red card for stretching his hand to block Shinji Kagawa's shot in the 3rd minute against Japan, denying an obvious goal scoring opportunity and giving away a penalty, which led to a 2–1 win for the Japanese. Then in the round-of-16, when defending a corner kick, he pulled down Harry Kane in the 57th minute to give away a penalty, which Kane converted.