Maxi is Newell's Old Boys captain and played for Martino last season.
He told AS: "Barca have got one of the best coaches that has come out of Argentina in recent times, without any doubt.
"Martino has always liked his teams to have the ball and play possession football, so he has a style of play that they are well used to seeing at the Camp Nou.
"He is a talker, he is close to his players, and he wants to listen in order to learn. Look how he changed the history of Newell's.
"When he arrived, the team were destined for relegation, which would have been a disaster. But all of us turned the situation around by believing in his message from day one and a few weeks ago on the streets of Rosario we celebrated winning the league title."