The 21-year-old's move from Santos to Camp Nou was subject to a lot of scrutiny in January, resulting in the resignation of Barca president Sandro Rosell amid fraudulent tax claims from the Spanish government and threats of legal action in Brazil.
Although Martino thinks that part of the reason for Neymar not being at his absolute best is his recovery from a sprained ankle, the Argentine coach thinks off-the-pitch issues have impacted the Brazilian.
"His position on the pitch hasn’t changed much since his return," he told reporters. "As a left winger or center forward his performances have been very good. Against Manchester City he played out right and he was very good. He’s fine playing in any of the three positions up front.
"Coming back from a month out it’s always hard to get your rhythm back and then all the difficulties with his signing came up. If I had to choose a reason (for his lack of sharpness), I’d say it was from things off the pitch."