[5] Ten years later, on 19 February 1991, he received his first call-up by new coach Alfio Basile to the senior squad for a friendly match against Hungary national football team.

[6] Martino was assigned as head coach of the Paraguay national football team in February 2007, replacing Uruguayan Anibal "Maño" Ruiz.

His knowledge and success while coaching Paraguayan clubs were the parameters that positioned him as the best option for the job (other candidates were Nery Pumpido and Miguel Ángel Russo).

In 2008, Martino was linked for vacant managerial position of Iran Pro League side Steel Azin, but the deal was cancelled for personal reasons.

As a result, Martino won further plaudits as a coach, having transformed Newell's from a team facing relegation on his arrival to a title-winning side, in addition to the arguably more impressive feat of reaching the 2013 Copa Libertadores semi-final, the pinnacle club competition organized by CONMEBOL.

It was this startling turnaround that further increased Martino's stock as a coach, and his achievements at Newell's soon caught the attention of various clubs in Europe, including Barcelona.

On 7 July 2013, Martino was confirmed as head coach of Spanish club Barcelona to replace Tito Vilanova, who resigned three days earlier due to health issues.

After conceding the 2013–14 La Liga title on the last day of the season to Atlético Madrid, Martino announced he was to leave his role after just one year in charge, during which he did not manage to win any major trophy except the Spanish Super Cup.

[16] On 12 August 2014, Martino was introduced as the new head coach for the Argentina national team, succeeding Alejandro Sabella who took the side into the final against Germany at the World Cup in Brazil.

[3] After departing from Argentina, Martino was announced as Major League Soccer expansion team Atlanta United's inaugural season head coach on 27 September 2016.

[19] On 23 October 2018, Martino announced that he would not renew his contract with Atlanta United following the conclusion of the 2018 MLS season, citing personal reasons.

This was further compounded with a 2–0 loss to the United States in World Cup qualifying in November, marking the first time in the rivalry since 1934 that one side had swept three matches against the other in a calendar year.