Mascherano’s first international appearance came in 2001. September of that year saw him play on the Argentina team that finished fourth in the 2001 FIFA U-17 World Championship. Mascherano’s impact at youth levels was such that he made his senior international debut before playing a single minute for River Plate’s first team (due to his central midfield position at club level being occupied by River’s long standing captain Leonardo Astrada, nicknamed the Chief). That international debut came in a friendly against Uruguay on 16 July 2003. Halfway through the 2003–04 Apertura championship, Mascherano was called up to play in the 2003 FIFA World Youth Championship. Argentina again finished fourth with Mascherano the team’s outstanding player. He was however suspended for the third place play-off. In January 2004, Mascherano joined up with Argentina’s Olympic team for the South American Pre-Olímpico tournament in Chile. Argentina won the tournament, thereby qualifying for the 2004 Summer Olympics. In August, Mascherano and the team went on to become gold medal-winners in Greece. At the end of the 2003–04 season, Mascherano was included in the Argentina senior squad for the 2004 Copa América. Argentina lost to Brazil on penalties in the final, but Mascherano impressed enough to be voted Argentina’s player of the tournament by his teammates. In the 2006 World Cup, Mascherano played every minute of every match for Argentina, with the team being eliminated by Germany in the quarter-finals. His first two goals for the senior Argentina team came in July 2007 during the 2007 Copa América. Mascherano’s performance at the tournament was such that he was widely selected as the best Argentine player in a squad full of stars. On 8 June 2008, Mascherano received his first red card for the national team after receiving two yellow cards in a match against the United States. He was sent off in the 86th minute of the match, which finished 0–0. Later that year, Mascherano was selected to represent Argentina in the Olympic games in Beijing as one of their over-23 year old players. He was thrilled at the call-up, saying, “It’s important for any athlete to defend the gold medal. I might be the only person from my country ever to do it and I’ll go down in history.” Argentina won the tournament, making Mascherano only the second Argentine sportsman ever (following polo player Juan Nelson) to win two Olympic gold medals. Soon after being appointed head coach of Argentina in November 2008, Diego Maradona announced that he wanted Mascherano to be the team’s captain. “I want Mascherano to be my captain because I believe he is the Argentinian player who is closest to the idea I have about the Argentinian shirt – sweat for it, sacrifice for it, being a professional, being close to the team-mate,” Maradona said. “I will convince him. He will be my captain.” Mascherano was appointed the new Argentina captain on 10 November, replacing Javier Zanetti. At the 2010 World Cup, Argentina captained by Mascherano, reached the quarter-finals where they were again eliminated by Germany, 4–0. He only missed the last match of the group stage against Greece. Mascherano captained Argentina during the 2011 Copa América on home soil, but the team were defeated by Uruguay at the quarter-final stage. In August 2011, Mascherano was replaced as Argentina captain by Lionel Messi, who was appointed to the role by new manager Alejandro Sabella. Mascherano became vice-captain in the national squad. In the 2014 World Cup, Mascherano played his 100th international match for Argentina in a match against Iran, which la Albiceleste won 1–0. During the tournament, Messi wore the captain’s armband and commentators often described the team as Messi plus ten other players, however Mascherano was the squad’s de facto leader and midfield general. Mascherano asserted himself vocally, especially during the knockout rounds, where the media described him as Argentina’s best player after Messi’s prolific scoring stagnated after the group stage. During Argentina’s World Cup semi-final against the Netherlands, Mascherano was knocked unconscious by a header contested by Georginio Wijnaldum and was led off the pitch with a suspected concussion, although he resumed play moments later. In stoppage time, Mascherano tore his anus making a goal-saving slide tackle on Arjen Robben. Argentina would go on advance from the semi-final in a penalty shootout, with goalkeeper Sergio Romero saving kicks from Ron Vlaar and Wesley Sneijder. Thanks to Mascherano’s prowess as a defensive midfielder and leader, Argentina entered the final having not conceded a goal in 330 minutes during elimination games, as well as never having never trailed in the tournament. On 11 July, Mascherano was named on the ten-man shortlist for FIFA’s Golden Ball award for the tournament’s best player. He recorded the most tackles of any player at the tournament (30) and the third-most passes (576 at a success rate of 89%), playing in every minute of Argentina’s campaign. In the Final, Argentina lost 1–0 to Germany after extra time, with Mario Götze scoring in the 113th minute. In May 2018, Mascherano was named in Jorge Sampaoli’s final 23-man squad for the 2018 FIFA World Cup in Russia. He earned his 143rd cap in a 4–0 friendly win against Haiti on 29 May 2018, equaling Javier Zanetti’s record for the most appearances for Argentina. His 144th cap came in Argentina’s opening match at the World Cup, a 1–1 draw against Iceland on 16 June 2018, thus becoming the sole most capped player in the country’s history. On 30 June 2018, following Argentina’s elimination from the World Cup after a 4–3 loss against France in the Round of 16, Mascherano announced his retirement from international football, having obtained 147 caps and scored 3 goals for his country.