The 22-year-old attacking midfielder was included in the Brazil starting line-up for the friendly international against Mexico.
Coutinho was in fine form in the game, as he opened the scoring just before the half-hour mark with a sublime strike for his first international goal.
Diego Tardelli added a second in the 37th minute to wrap up a 2-0 win for the South American giants.
Former Inter Milan youngster Coutinho was in superb form in the second half of the recently concluded 2014-15 season.
The Brazilian scored five goals and created 58 chances in 35 Premier League appearances, and had a pass accuracy of 80% and a shot accuracy of 53%.
Coutinho won four headers, 109 dribbles and 49 tackles in those 35 league matches.
Following Coutinho’s performance for Brazil, Liverpool fans took to Twitter to give their reaction.
Coutinho's debut goal for Brazil was top class! Expecting big things from him next season now that he's the main man! #LFC— Luke Terry (@TerrysReds) June 8, 2015