The Brazilian was named player of the tournament as the Nerazzurri overcame AC Milan and Juventus, and he believes the coach has had a great impact on the club
The Nerazzurri triumphed in the traditional pre-season tournament by defeating both Juventus and AC Milan in Bari.
The Brazilian, who had a spell on loan at Espanyol last season, had a great impact on the event, scoring the winning goal against the Bianconeri and claiming the player of the tournament gong.
"I'm doing well and, thanks to the confidence of Stramaccioni, things are going better," he told reporters after the match.
"We were set up well on the pitch, I was on the left and I was ready when the Juventus defence got a little careless."
And Coutinho voiced his hope that compatriot Lucas Moura would soon be joining him at San Siro from Sao Paulo.
"I hope that he arrives. He is a champion, but it's not up to me to decide these things," he said. "The club make the decisions in the market."
Since making his full international debut in 2010, Coutinho has won five caps for the Selecaoand was part of the team that won the Under-20 World Cup in 2011.