The Brazil international was given his first taste of Camp Nou action in Thursday night's Copa del Rey second-leg tie after shaking off a minor calf injury.
Coutinho, who joined from Liverpool in a £142m deal at the start of the January transfer window, is happy to have got some minutes under his belt and played a part in Barca's 2-1 aggregate triumph.
"For me it's a great night, a very special night," he told reporters at full time. "They are my first minutes with this club and I'm very happy, thrilled.
"The reception I got from the fans and the players left me happy. I was a little anxious, nervous, but the way they all received me left me very calm.
"It's a special night and we've managed to win the game, which is the most important thing. It was a difficult game, as you'd expect, against a team who played well. I think from the first half we controlled the game well and we've deserved to win."
Barcelona will face either Valencia, Sevilla or Leganes in the final four of the domestic cup competition.