The Argentina international has acknowledged that things have changed under the 51-year-old, while admitting Tito Vilanova's illness was hard to deal with
Lionel Messi believes Barcelona can "feel the difference" since Gerardo Martino took charge of the club.
Martino took over at Camp Nou in July 2013 after Tito Vilanova left his position with the Spanish champions, having suffered a cancer relapse.
Messi feels the former Newell's Old Boys boss has brought his own ideas to the club.
"Every coach has his own ideas," the Argentine told reporters.
"We had Tito before, but maybe we didn't see any differences with [Pep] Guardiola's style because he was working besides him and most of the squad already knew his style.
"However, now with Tata, who came from outside the club, we can feel the difference."
Messi added that Vilanova's health issues had proved difficult for the players to deal with, particularly in light of Eric Abidal's battle against liver cancer.
"It was tough for everybody because it happened after Abidal's cancer and then it was Tito," he continued
"It was very complicated because the dressing room loved Tito and Abidal, and it was a great blow for the whole squad."