Lazio are into the semifinals after winning a penalty shootout at Bologna on Wednesday.
Sarri later said: "We haven't lost away since November, and we've been doing well for three or four months. We're doing what we can, maybe even more.
"I'm happy for my players and for all Lazio fans. The Coppa Italia campaign is clearly very tough.
"It's refreshing, you feel like you've created a real group. People who think about football the same way. The credit goes to the guys: all the season's difficulties created problems for us, but they also gave us the opportunity to build a united group."
Sarri also commented on the performances of Alessio Romagnoli and Daniel Maldini on the night.
He added, "Romagnoli is an important player for us. Regardless of his performance, he's the one who controls the defensive line. If Maldini can make progress, he can do it.
" In this match, we also wanted a central striker who could step up. He has important technical and physical qualities, but he can't exploit them 100% yet, but I have hope."