The Argentine winger scored two goals in the quarter-final second-leg win over Levante in midweek and is now targeting progression past the Catalan giants in the next stage
The Argentine winger scored a brace in the convincing 3-0 win over Levante in the second leg of the quarter-finals to set up the glamour tie against Pep Guardiola's men, a challenge which he feels Los Che have the tools to overcome.
"I have no doubt we can beat Barcelona," the 22-year-old told AS.
"The team is passionate and we are looking forward to it. They will be two very complicated matches and we will need great effort, but we will try to use all our weapons."
Piatti also grabbed one of the goals in the 4-1 first-leg win over Levante, his first for the club, and the South American is looking to continue his progression at the Mestalla.
"I have always said that mentality is a very important factor," the youngster added of his development.
"I have never stopped working and trying, sooner or later results appear, but the three goals were a fluke.
"I still have a lot to prove in Valencia, but I have a lot of confidence. I always talk to [coach Unai] Emery and he has made it clear that he will continue to give me a chance."
Valencia take on Racing Santander in La Liga on Sunday, hoping to close the nine-point gap on Barcelona in second.