Rafael Benitez's side are just three points behind second place Roma and entertain Fiorentina on Sunday, who were also knocked out of the Europa League on Thursday.
The two sides will also meet in the Coppa Italia in May and Henrique wants success in both competitions to make up for agony on the European stage.
"We are sad because we had the opportunity to be able to continue the adventure in Europe," he said.
"Now, however, we look forward, we think about the championship and try to win second place. This is a very important game for us.
"We want to win and play a great game at the San Paolo to go for second place - then we will play in the final of the Italian Cup, but for the moment we only think about th match on Sunday.
"We are aiming to return to the Champions League and then next year we can play one more season important."
Napoli have lost just four league games under Benitez and won th ill-tempered reverse fixture in Fiorentina back in October.
While Napoli were knocked out by Porto, Fiorentina were beaten by Serie A leaders Juventus and - much like Henrique - Viola coach Vincenzo Montella wants to recover quickly and cement fourth place.
"We're disappointed," he said of Fiorentina's cup exit.
"But now we have to turn the page and get our focus back on the league, where we have another set of objectives."
Although they sit just one place below Napoli in the table, Fiorentina are more likely to be looking over their shoulder as they are 10 points adrift of the top three but only one ahead of fifth-placed Inter Milan.