Barcelona have made Gerardo "Tata" Martino their new coach. The Argentinian, who led Newell's Old Boys to the semi-final of the Copa Libertadores, will sign a three-year deal at the Camp Nou, following Tito Vilanova's decision on Friday to resign because of a recurrence of the cancer that he first suffered in 2011.

Martino will be accompanied by his normal backroom team, including the assistants Elvio Paolorroso and Jorge Pautasso. It is not yet clear if Vilanova's assistants, Jordi Roura and the recently signed Joan Francesc Ferrer Sicilia, known as Rubí, will continue.

Barcelona spoke to the 50-year-old Martino before the weekend, as soon as they knew that Vilanova had to step down, and they reached an agreement by video conference call on Monday morning. Barcelona hope to make a formal announcement and hold a presentation in the coming days. Contracts are still to be formalised, however, and Martino is not expected in Barcelona until Wednesday – too late to take charge of the club's friendly against Pep Guardiola's Bayern Munich.

Timing has been a key factor in the appointment, both from the perspective of the club and that of the coach. Real Sociedad and Málaga had approached Martino about taking over as manager this season. One of the reasons that he turned both clubs down was that Newell's were still competing in the Copa Libertadores. A semi-final defeat to Atlético Mineiro meant that he is now available.

Barcelona also spoke to the former midfielder and Barcelona B team coach Luis Enrique, who was widely considered the favourite. Luis Enrique, though, had only recently committed his future to Celta Vigo for the coming season. The other man that Barcelona had in mind as manager, both when Guardiola stepped down and early this summer, was Ernesto Valverde. But with Vilanova believing at the time that he was well enough to continue, Valverde agreed to join Athletic Bilbao.

It remains to be seen whether the final decision came from the board and the president, Sandro Rosell, or the sporting director, Andoni Zubizarreta. There has also been some suggestion that in consultation with the squad, Martino emerged as a more popular appointment than Luis Enrique. Leo Messi, like Martino born in Rosario, publicly praised him more than a year ago and Martino is an admirer of the Barcelona player. "It turns out that 20 years later, we [Argentinians] have the best player in the world again," he said.