Club career
Pochettino started his professional career with Newell's Old Boys, moving to RCD Espanyol in Spain in 1994–95, as the Catalans had just returned to La Liga. He was an undisputed starter in his six 1/2 season spell, helping the club to the 2000 Spanish Cup.

In late January 2009, Pochettino became Espanyol's third coach in 2008–09, with the side then ranking third from bottom, but eventually finishing the season comfortably placed (10th), after the coach inclusively asked for "divine intervention". He coached nine club players who were his teammates during his last season and, in early June, renewed his link for a further three years.

In the 2009–10 season, Pochettino once again led Espanyol to a comfortable league position, in a campaign where club symbol (and his former teammate) Raúl Tamudo fell completely out of favour in the squad's rotation, even more after the January 2010 arrival of manager compatriot Pablo Osvaldo.

On 28 September 2010, he extended his contract with the club for one more year, until 30 June 2012.

International career
Pochettino played for Argentina 20 times during four years, and was a participant at the 2002 FIFA World Cup, playing three complete matches as the nation exited in the group stage.

In the second match against England, he brought down Michael Owen in the box. The resulting penalty was converted by David Beckham, for the game's only goal