The Blaugrana trainer has explained that he was first contacted by the Catalans through the president of Paraguay, Horacio Cartes
The former Newell's Old Boys boss was a surprise choice to succeed Tito Vilanova and the 50-year-old has admitted that the Blaugrana's offer also took him aback, coming as it did via the former president of Paraguay.
“It all came about through Horacio Cartes," Martino is quoted as saying by AS. "I met Rosell at a dinner at Cartes' house [when Cartes was President at Paraguayan club, Libertad].
"Later, when Barcelona were looking for a new coach but didn’t know how to contact me, Rosell called Cartes, and that's how it all began.
"I had no idea about what was happening until I'd spoken to Rosell. He told me he wanted to put me in touch with [Andoni] Zubizarreta and a few days later we started to talk. I didn't even mention it to my wife!"
Having never before coached in La Liga, Martino freely admits that he has been very much thrown in at the deep end.
"It's all very exciting, but I'm really enjoying it," he enthused. "It’s a great job to have and I am very excited by it but it also brings a great deal of responsibility.
"Making the leap from South America to Europe is a bit daunting. Under other circumstances, I would probably have already started my career in Spain before taking on a big job like the Barca post."
However, Martino fully expects Newell's Old Boys youth team product Lionel Messi to make his life very easy.
“Game after game, he just keeps surprising everyone - myself included," the once-capped Argentina international enthused.
"You can tell that one day he eventually wants to go back to Rosario and maybe go back to Newell’s.
"As a coach, I can see what he might be thinking but I could never have imagined that I would be coaching him now, at Barca, like this."
Martino has penned a two-year contract with the Blaugrana, who won the Spanish title last year but were embarrassed by Bayern Munich in the semi-finals of the Champions League.